6 files changed, 0 insertions, 3047 deletions

diff --git a/ext/expert/README.md b/ext/expert/README.md
deleted file mode 100644
index 28886fd1f2d7..000000000000
--- a/ext/expert/README.md
+++ /dev/null
@@ -1,83 +0,0 @@
-## SQLite Expert Extension
-
-This folder contains code for a simple system to propose useful indexes
-given a database and a set of SQL queries. It works as follows:
-
-  1. The user database schema is copied to a temporary database.
-
-  1. All SQL queries are prepared against the temporary database.
-     Information regarding the WHERE and ORDER BY clauses, and other query
-     features that affect index selection are recorded.
-
-  1. The information gathered in step 2 is used to create candidate 
-     indexes - indexes that the planner might have made use of in the previous
-     step, had they been available.
-
-  1. A subset of the data in the user database is used to generate statistics
-     for all existing indexes and the candidate indexes generated in step 3
-     above.
-
-  1. The SQL queries are prepared a second time. If the planner uses any
-     of the indexes created in step 3, they are recommended to the user.
-
-# C API
-
-The SQLite expert C API is defined in sqlite3expert.h. Most uses will proceed
-as follows:
-
-  1. An sqlite3expert object is created by calling **sqlite3\_expert\_new()**.
-     A database handle opened by the user is passed as an argument.
-
-  1. The sqlite3expert object is configured with one or more SQL statements
-     by making one or more calls to **sqlite3\_expert\_sql()**. Each call may
-     specify a single SQL statement, or multiple statements separated by
-     semi-colons.
-  
-  1. Optionally, the **sqlite3\_expert\_config()** API may be used to 
-     configure the size of the data subset used to generate index statistics.
-     Using a smaller subset of the data can speed up the analysis.
-
-  1. **sqlite3\_expert\_analyze()** is called to run the analysis.
-
-  1. One or more calls are made to **sqlite3\_expert\_report()** to extract
-     components of the results of the analysis.
-
-  1. **sqlite3\_expert\_destroy()** is called to free all resources.
-
-Refer to comments in sqlite3expert.h for further details.
-
-# sqlite3_expert application
-
-The file "expert.c" contains the code for a command line application that
-uses the API described above. It can be compiled with (for example):
-
-<pre>
-  gcc -O2 sqlite3.c expert.c sqlite3expert.c -o sqlite3_expert
-</pre>
-
-Assuming the database is named "test.db", it can then be run to analyze a
-single query:
-
-<pre>
-  ./sqlite3_expert -sql &lt;sql-query&gt; test.db
-</pre>
-
-Or an entire text file worth of queries with:
-
-<pre>
-  ./sqlite3_expert -file &lt;text-file&gt; test.db
-</pre>
-
-By default, sqlite3\_expert generates index statistics using all the data in
-the user database. For a large database, this may be prohibitively time
-consuming. The "-sample" option may be used to configure sqlite3\_expert to
-generate statistics based on an integer percentage of the user database as
-follows:
-
-<pre>
-  # Generate statistics based on 25% of the user database rows:
-  ./sqlite3_expert -sample 25 -sql &lt;sql-query&gt; test.db
-
-  # Do not generate any statistics at all:
-  ./sqlite3_expert -sample 0 -sql &lt;sql-query&gt; test.db
-</pre>
diff --git a/ext/expert/expert.c b/ext/expert/expert.c
deleted file mode 100644
index 051480f89602..000000000000
--- a/ext/expert/expert.c
+++ /dev/null
@@ -1,156 +0,0 @@
-/*
-** 2017 April 07
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-*/
-
-
-#include <sqlite3.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "sqlite3expert.h"
-
-
-static void option_requires_argument(const char *zOpt){
-  fprintf(stderr, "Option requires an argument: %s\n", zOpt);
-  exit(-3);
-}
-
-static int option_integer_arg(const char *zVal){
-  return atoi(zVal);
-}
-
-static void usage(char **argv){
-  fprintf(stderr, "\n");
-  fprintf(stderr, "Usage %s ?OPTIONS? DATABASE\n", argv[0]);
-  fprintf(stderr, "\n");
-  fprintf(stderr, "Options are:\n");
-  fprintf(stderr, "  -sql SQL   (analyze SQL statements passed as argument)\n");
-  fprintf(stderr, "  -file FILE (read SQL statements from file FILE)\n");
-  fprintf(stderr, "  -verbose LEVEL (integer verbosity level. default 1)\n");
-  fprintf(stderr, "  -sample PERCENT (percent of db to sample. default 100)\n");
-  exit(-1);
-}
-
-static int readSqlFromFile(sqlite3expert *p, const char *zFile, char **pzErr){
-  FILE *in = fopen(zFile, "rb");
-  long nIn;
-  size_t nRead;
-  char *pBuf;
-  int rc;
-  if( in==0 ){
-    *pzErr = sqlite3_mprintf("failed to open file %s\n", zFile);
-    return SQLITE_ERROR;
-  }
-  fseek(in, 0, SEEK_END);
-  nIn = ftell(in);
-  rewind(in);
-  pBuf = sqlite3_malloc64( nIn+1 );
-  nRead = fread(pBuf, nIn, 1, in);
-  fclose(in);
-  if( nRead!=1 ){
-    sqlite3_free(pBuf);
-    *pzErr = sqlite3_mprintf("failed to read file %s\n", zFile);
-    return SQLITE_ERROR;
-  }
-  pBuf[nIn] = 0;
-  rc = sqlite3_expert_sql(p, pBuf, pzErr);
-  sqlite3_free(pBuf);
-  return rc;
-}
-
-int main(int argc, char **argv){
-  const char *zDb;
-  int rc = 0;
-  char *zErr = 0;
-  int i;
-  int iVerbose = 1;               /* -verbose option */
-
-  sqlite3 *db = 0;
-  sqlite3expert *p = 0;
-
-  if( argc<2 ) usage(argv);
-  zDb = argv[argc-1];
-  if( zDb[0]=='-' ) usage(argv);
-  rc = sqlite3_open(zDb, &db);
-  if( rc!=SQLITE_OK ){
-    fprintf(stderr, "Cannot open db file: %s - %s\n", zDb, sqlite3_errmsg(db));
-    exit(-2);
-  }
-
-  p = sqlite3_expert_new(db, &zErr);
-  if( p==0 ){
-    fprintf(stderr, "Cannot run analysis: %s\n", zErr);
-    rc = 1;
-  }else{
-    for(i=1; i<(argc-1); i++){
-      char *zArg = argv[i];
-      int nArg;
-      if( zArg[0]=='-' && zArg[1]=='-' && zArg[2]!=0 ) zArg++;
-      nArg = (int)strlen(zArg);
-      if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-file", nArg) ){
-        if( ++i==(argc-1) ) option_requires_argument("-file");
-        rc = readSqlFromFile(p, argv[i], &zErr);
-      }
-
-      else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sql", nArg) ){
-        if( ++i==(argc-1) ) option_requires_argument("-sql");
-        rc = sqlite3_expert_sql(p, argv[i], &zErr);
-      }
-
-      else if( nArg>=3 && 0==sqlite3_strnicmp(zArg, "-sample", nArg) ){
-        int iSample;
-        if( ++i==(argc-1) ) option_requires_argument("-sample");
-        iSample = option_integer_arg(argv[i]);
-        sqlite3_expert_config(p, EXPERT_CONFIG_SAMPLE, iSample);
-      }
-
-      else if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-verbose", nArg) ){
-        if( ++i==(argc-1) ) option_requires_argument("-verbose");
-        iVerbose = option_integer_arg(argv[i]);
-      }
-
-      else{
-        usage(argv);
-      }
-    }
-  }
-
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_expert_analyze(p, &zErr);
-  }
-
-  if( rc==SQLITE_OK ){
-    int nQuery = sqlite3_expert_count(p);
-    if( iVerbose>0 ){
-      const char *zCand = sqlite3_expert_report(p,0,EXPERT_REPORT_CANDIDATES);
-      fprintf(stdout, "-- Candidates -------------------------------\n");
-      fprintf(stdout, "%s\n", zCand);
-    }
-    for(i=0; i<nQuery; i++){
-      const char *zSql = sqlite3_expert_report(p, i, EXPERT_REPORT_SQL);
-      const char *zIdx = sqlite3_expert_report(p, i, EXPERT_REPORT_INDEXES);
-      const char *zEQP = sqlite3_expert_report(p, i, EXPERT_REPORT_PLAN);
-      if( zIdx==0 ) zIdx = "(no new indexes)\n";
-      if( iVerbose>0 ){
-        fprintf(stdout, "-- Query %d ----------------------------------\n",i+1);
-        fprintf(stdout, "%s\n\n", zSql);
-      }
-      fprintf(stdout, "%s\n%s\n", zIdx, zEQP);
-    }
-  }else{
-    fprintf(stderr, "Error: %s\n", zErr ? zErr : "?");
-  }
-
-  sqlite3_expert_destroy(p);
-  sqlite3_free(zErr);
-  return rc;
-}
diff --git a/ext/expert/expert1.test b/ext/expert/expert1.test
deleted file mode 100644
index 0e6fc8260494..000000000000
--- a/ext/expert/expert1.test
+++ /dev/null
@@ -1,458 +0,0 @@
-# 2009 Nov 11
-#
-# The author disclaims copyright to this source code.  In place of
-# a legal notice, here is a blessing:
-#
-#    May you do good and not evil.
-#    May you find forgiveness for yourself and forgive others.
-#    May you share freely, never taking more than you give.
-#
-#***********************************************************************
-#
-# The focus of this file is testing the CLI shell tool. Specifically,
-# the ".recommend" command.
-#
-#
-
-# Test plan:
-#
-#
-if {![info exists testdir]} {
-  set testdir [file join [file dirname [info script]] .. .. test]
-}
-source $testdir/tester.tcl
-set testprefix expert1
-
-if {[info commands sqlite3_expert_new]==""} {
-  finish_test
-  return
-}
-
-
-set CLI [test_binary_name sqlite3]
-set CMD [test_binary_name sqlite3_expert]
-
-proc squish {txt} {
-  regsub -all {[[:space:]]+} $txt { }
-}
-
-proc do_setup_rec_test {tn setup sql res} {
-  reset_db
-  if {[info exists ::set_main_db_name]} {
-    dbconfig_maindbname_icecube db
-  }
-  db eval $setup
-  uplevel [list do_rec_test $tn $sql $res]
-}
-
-foreach {tn setup} {
-  1 {
-    if {![file executable $CMD]} { continue }
-
-    proc do_rec_test {tn sql res} {
-      set res [squish [string trim $res]]
-      set tst [subst -nocommands { 
-        squish [string trim [exec $::CMD -verbose 0 -sql {$sql;} test.db]]
-      }]
-      uplevel [list do_test $tn $tst $res]
-    }
-  }
-  2 {
-    if {[info commands sqlite3_expert_new]==""} { continue }
-
-    proc do_rec_test {tn sql res} {
-      set expert [sqlite3_expert_new db]
-      $expert sql $sql
-      $expert analyze
-
-      set result [list]
-      for {set i 0} {$i < [$expert count]} {incr i} {
-        set idx [string trim [$expert report $i indexes]]
-        if {$idx==""} {set idx "(no new indexes)"}
-        lappend result $idx
-        lappend result [string trim [$expert report $i plan]]
-      }
-
-      $expert destroy
-
-      set tst [subst -nocommands {set {} [squish [join {$result}]]}]
-      uplevel [list do_test $tn $tst [string trim [squish $res]]]
-    }
-  }
-  3 {
-    if {[info commands sqlite3_expert_new]==""} { continue }
-    set ::set_main_db_name 1
-  }
-  4 {
-    if {![file executable $CLI]} { continue }
-
-    proc do_rec_test {tn sql res} {
-      set res [squish [string trim $res]]
-      set tst [subst -nocommands { 
-        squish [string trim [exec $::CLI test.db ".expert" {$sql;}]]
-      }]
-      uplevel [list do_test $tn $tst $res]
-    }
-  }
-} {
-
-  eval $setup
-
-
-do_setup_rec_test $tn.1 { CREATE TABLE t1(a, b, c) } {
-  SELECT * FROM t1
-} {
-  (no new indexes)
-  SCAN TABLE t1
-}
-
-do_setup_rec_test $tn.2 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT * FROM t1 WHERE b>?;
-} {
-  CREATE INDEX t1_idx_00000062 ON t1(b);
-  SEARCH TABLE t1 USING INDEX t1_idx_00000062 (b>?)
-}
-
-do_setup_rec_test $tn.3 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT * FROM t1 WHERE b COLLATE nocase BETWEEN ? AND ?
-} {
-  CREATE INDEX t1_idx_3e094c27 ON t1(b COLLATE NOCASE);
-  SEARCH TABLE t1 USING INDEX t1_idx_3e094c27 (b>? AND b<?)
-}
-
-do_setup_rec_test $tn.4 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT a FROM t1 ORDER BY b;
-} {
-  CREATE INDEX t1_idx_00000062 ON t1(b);
-  SCAN TABLE t1 USING INDEX t1_idx_00000062
-}
-
-do_setup_rec_test $tn.5 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT a FROM t1 WHERE a=? ORDER BY b;
-} {
-  CREATE INDEX t1_idx_000123a7 ON t1(a, b);
-  SEARCH TABLE t1 USING COVERING INDEX t1_idx_000123a7 (a=?)
-}
-
-if 0 {
-do_setup_rec_test $tn.6 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT min(a) FROM t1
-} {
-  CREATE INDEX t1_idx_00000061 ON t1(a);
-  SEARCH TABLE t1 USING COVERING INDEX t1_idx_00000061
-}
-}
-
-do_setup_rec_test $tn.7 {
-  CREATE TABLE t1(a, b, c);
-} {
-  SELECT * FROM t1 ORDER BY a, b, c;
-} {
-  CREATE INDEX t1_idx_033e95fe ON t1(a, b, c);
-  SCAN TABLE t1 USING COVERING INDEX t1_idx_033e95fe
-}
-
-#do_setup_rec_test $tn.1.8 {
-#  CREATE TABLE t1(a, b, c);
-#} {
-#  SELECT * FROM t1 ORDER BY a ASC, b COLLATE nocase DESC, c ASC;
-#} {
-#  CREATE INDEX t1_idx_5be6e222 ON t1(a, b COLLATE NOCASE DESC, c);
-#  0|0|0|SCAN TABLE t1 USING COVERING INDEX t1_idx_5be6e222
-#}
-
-do_setup_rec_test $tn.8.1 {
-  CREATE TABLE t1(a COLLATE NOCase, b, c);
-} {
-  SELECT * FROM t1 WHERE a=?
-} {
-  CREATE INDEX t1_idx_00000061 ON t1(a);
-  SEARCH TABLE t1 USING INDEX t1_idx_00000061 (a=?)
-}
-do_setup_rec_test $tn.8.2 {
-  CREATE TABLE t1(a, b COLLATE nocase, c);
-} {
-  SELECT * FROM t1 ORDER BY a ASC, b DESC, c ASC;
-} {
-  CREATE INDEX t1_idx_5cb97285 ON t1(a, b DESC, c);
-  SCAN TABLE t1 USING COVERING INDEX t1_idx_5cb97285
-}
-
-
-# Tables with names that require quotes.
-#
-do_setup_rec_test $tn.9.1 {
-  CREATE TABLE "t t"(a, b, c);
-} {
-  SELECT * FROM "t t" WHERE a=?
-} {
-  CREATE INDEX 't t_idx_00000061' ON 't t'(a);
-  SEARCH TABLE t t USING INDEX t t_idx_00000061 (a=?) 
-}
-
-do_setup_rec_test $tn.9.2 {
-  CREATE TABLE "t t"(a, b, c);
-} {
-  SELECT * FROM "t t" WHERE b BETWEEN ? AND ?
-} {
-  CREATE INDEX 't t_idx_00000062' ON 't t'(b);
-  SEARCH TABLE t t USING INDEX t t_idx_00000062 (b>? AND b<?)
-}
-
-# Columns with names that require quotes.
-#
-do_setup_rec_test $tn.10.1 {
-  CREATE TABLE t3(a, "b b", c);
-} {
-  SELECT * FROM t3 WHERE "b b" = ?
-} {
-  CREATE INDEX t3_idx_00050c52 ON t3('b b');
-  SEARCH TABLE t3 USING INDEX t3_idx_00050c52 (b b=?)
-}
-
-do_setup_rec_test $tn.10.2 {
-  CREATE TABLE t3(a, "b b", c);
-} {
-  SELECT * FROM t3 ORDER BY "b b"
-} {
-  CREATE INDEX t3_idx_00050c52 ON t3('b b');
-  SCAN TABLE t3 USING INDEX t3_idx_00050c52
-}
-
-# Transitive constraints
-#
-do_setup_rec_test $tn.11.1 {
-  CREATE TABLE t5(a, b);
-  CREATE TABLE t6(c, d);
-} {
-  SELECT * FROM t5, t6 WHERE a=? AND b=c AND c=?
-} {
-  CREATE INDEX t5_idx_000123a7 ON t5(a, b);
-  CREATE INDEX t6_idx_00000063 ON t6(c);
-  SEARCH TABLE t6 USING INDEX t6_idx_00000063 (c=?) 
-  SEARCH TABLE t5 USING COVERING INDEX t5_idx_000123a7 (a=? AND b=?)
-}
-
-# OR terms.
-#
-do_setup_rec_test $tn.12.1 {
-  CREATE TABLE t7(a, b);
-} {
-  SELECT * FROM t7 WHERE a=? OR b=?
-} {
-  CREATE INDEX t7_idx_00000062 ON t7(b);
-  CREATE INDEX t7_idx_00000061 ON t7(a);
-  MULTI-INDEX OR
-    INDEX 1
-      SEARCH TABLE t7 USING INDEX t7_idx_00000061 (a=?) 
-    INDEX 2
-      SEARCH TABLE t7 USING INDEX t7_idx_00000062 (b=?)
-}
-
-# rowid terms.
-#
-do_setup_rec_test $tn.13.1 {
-  CREATE TABLE t8(a, b);
-} {
-  SELECT * FROM t8 WHERE rowid=?
-} {
-  (no new indexes)
-  SEARCH TABLE t8 USING INTEGER PRIMARY KEY (rowid=?)
-}
-do_setup_rec_test $tn.13.2 {
-  CREATE TABLE t8(a, b);
-} {
-  SELECT * FROM t8 ORDER BY rowid
-} {
-  (no new indexes)
-  SCAN TABLE t8
-}
-do_setup_rec_test $tn.13.3 {
-  CREATE TABLE t8(a, b);
-} {
-  SELECT * FROM t8 WHERE a=? ORDER BY rowid
-} {
-  CREATE INDEX t8_idx_00000061 ON t8(a); 
-  SEARCH TABLE t8 USING INDEX t8_idx_00000061 (a=?)
-}
-
-# Triggers
-#
-do_setup_rec_test $tn.14 {
-  CREATE TABLE t9(a, b, c);
-  CREATE TABLE t10(a, b, c);
-  CREATE TRIGGER t9t AFTER INSERT ON t9 BEGIN
-    UPDATE t10 SET a=new.a WHERE b = new.b;
-  END;
-} {
-  INSERT INTO t9 VALUES(?, ?, ?);
-} {
-  CREATE INDEX t10_idx_00000062 ON t10(b); 
-  SEARCH TABLE t10 USING INDEX t10_idx_00000062 (b=?)
-}
-
-do_setup_rec_test $tn.15 {
-  CREATE TABLE t1(a, b);
-  CREATE TABLE t2(c, d);
-
-  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
-  INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;
-
-  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
-  INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
-} {
-  SELECT * FROM t2, t1 WHERE b=? AND d=? AND t2.rowid=t1.rowid
-} {
-  CREATE INDEX t2_idx_00000064 ON t2(d);
-  SEARCH TABLE t2 USING INDEX t2_idx_00000064 (d=?) 
-  SEARCH TABLE t1 USING INTEGER PRIMARY KEY (rowid=?)
-}
-
-do_setup_rec_test $tn.16 {
-  CREATE TABLE t1(a, b);
-} {
-  SELECT * FROM t1 WHERE b IS NOT NULL;
-} {
-  (no new indexes)
-  SCAN TABLE t1
-}
-
-do_setup_rec_test $tn.17.1 {
-  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
-} {
-  SELECT * FROM example WHERE a=?
-} {
-  (no new indexes)
-  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=?)
-}
-do_setup_rec_test $tn.17.2 {
-  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
-} {
-  SELECT * FROM example WHERE b=?
-} {
-  CREATE INDEX example_idx_00000042 ON example(B);
-  SEARCH TABLE example USING INDEX example_idx_00000042 (B=?)
-}
-do_setup_rec_test $tn.17.3 {
-  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
-} {
-  SELECT * FROM example WHERE a=? AND b=?
-} {
-  (no new indexes)
-  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=? AND B=?)
-}
-do_setup_rec_test $tn.17.4 {
-  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
-} {
-  SELECT * FROM example WHERE a=? AND b>?
-} {
-  (no new indexes)
-  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=? AND B>?)
-}
-do_setup_rec_test $tn.17.5 {
-  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
-} {
-  SELECT * FROM example WHERE a>? AND b=?
-} {
-  CREATE INDEX example_idx_0000cb3f ON example(B, A);
-  SEARCH TABLE example USING INDEX example_idx_0000cb3f (B=? AND A>?)
-}
-
-do_setup_rec_test $tn.18.0 {
-  CREATE TABLE SomeObject (
-     a INTEGER PRIMARY KEY,
-     x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
-  );
-} {
-  SELECT x FROM SomeObject;
-} {
-  (no new indexes)
-  SCAN TABLE SomeObject
-}
-do_setup_rec_test $tn.18.1 {
-  CREATE TABLE SomeObject (
-     a INTEGER PRIMARY KEY,
-     x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
-  );
-} {
-  SELECT * FROM SomeObject WHERE x=?;
-} {
-  CREATE INDEX SomeObject_idx_00000078 ON SomeObject(x);
-  SEARCH TABLE SomeObject USING COVERING INDEX SomeObject_idx_00000078 (x=?)
-}
-
-}
-
-proc do_candidates_test {tn sql res} {
-  set res [squish [string trim $res]]
-
-  set expert [sqlite3_expert_new db]
-  $expert sql $sql
-  $expert analyze
-
-  set candidates [squish [string trim [$expert report 0 candidates]]]
-  $expert destroy
-
-  uplevel [list do_test $tn [list set {} $candidates] $res]
-}
-
-
-reset_db
-do_execsql_test 5.0 {
-  CREATE TABLE t1(a, b);
-  CREATE TABLE t2(c, d);
-
-  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
-  INSERT INTO t1 SELECT (i-1)/50, (i-1)/20 FROM s;
-
-  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100)
-  INSERT INTO t2 SELECT (i-1)/20, (i-1)/5 FROM s;
-}
-do_candidates_test 5.1 {
-  SELECT * FROM t1,t2 WHERE (b=? OR a=?) AND (c=? OR d=?)
-} {
-  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
-  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
-  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
-  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
-}
-
-do_candidates_test 5.2 {
-  SELECT * FROM t1,t2 WHERE a=? AND b=? AND c=? AND d=?
-} {
-  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 17
-  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
-}
-
-do_execsql_test 5.3 {
-  CREATE INDEX t1_idx_00000061 ON t1(a); -- stat1: 100 50 
-  CREATE INDEX t1_idx_00000062 ON t1(b); -- stat1: 100 20 
-  CREATE INDEX t1_idx_000123a7 ON t1(a, b); -- stat1: 100 50 16
-
-  CREATE INDEX t2_idx_00000063 ON t2(c); -- stat1: 100 20 
-  CREATE INDEX t2_idx_00000064 ON t2(d); -- stat1: 100 5
-  CREATE INDEX t2_idx_0001295b ON t2(c, d); -- stat1: 100 20 5
-
-  ANALYZE;
-  SELECT * FROM sqlite_stat1 ORDER BY 1, 2;
-} {
-  t1 t1_idx_00000061 {100 50} 
-  t1 t1_idx_00000062 {100 20}
-  t1 t1_idx_000123a7 {100 50 17}
-  t2 t2_idx_00000063 {100 20} 
-  t2 t2_idx_00000064 {100 5} 
-  t2 t2_idx_0001295b {100 20 5}
-}
-
-finish_test
-
diff --git a/ext/expert/sqlite3expert.c b/ext/expert/sqlite3expert.c
deleted file mode 100644
index 863c6a34098c..000000000000
--- a/ext/expert/sqlite3expert.c
+++ /dev/null
@@ -1,1962 +0,0 @@
-/*
-** 2017 April 09
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-*/
-#include "sqlite3expert.h"
-#include <assert.h>
-#include <string.h>
-#include <stdio.h>
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE 
-
-typedef sqlite3_int64 i64;
-typedef sqlite3_uint64 u64;
-
-typedef struct IdxColumn IdxColumn;
-typedef struct IdxConstraint IdxConstraint;
-typedef struct IdxScan IdxScan;
-typedef struct IdxStatement IdxStatement;
-typedef struct IdxTable IdxTable;
-typedef struct IdxWrite IdxWrite;
-
-#define STRLEN  (int)strlen
-
-/*
-** A temp table name that we assume no user database will actually use.
-** If this assumption proves incorrect triggers on the table with the
-** conflicting name will be ignored.
-*/
-#define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776"
-
-/*
-** A single constraint. Equivalent to either "col = ?" or "col < ?" (or
-** any other type of single-ended range constraint on a column).
-**
-** pLink:
-**   Used to temporarily link IdxConstraint objects into lists while
-**   creating candidate indexes.
-*/
-struct IdxConstraint {
-  char *zColl;                    /* Collation sequence */
-  int bRange;                     /* True for range, false for eq */
-  int iCol;                       /* Constrained table column */
-  int bFlag;                      /* Used by idxFindCompatible() */
-  int bDesc;                      /* True if ORDER BY <expr> DESC */
-  IdxConstraint *pNext;           /* Next constraint in pEq or pRange list */
-  IdxConstraint *pLink;           /* See above */
-};
-
-/*
-** A single scan of a single table.
-*/
-struct IdxScan {
-  IdxTable *pTab;                 /* Associated table object */
-  int iDb;                        /* Database containing table zTable */
-  i64 covering;                   /* Mask of columns required for cov. index */
-  IdxConstraint *pOrder;          /* ORDER BY columns */
-  IdxConstraint *pEq;             /* List of == constraints */
-  IdxConstraint *pRange;          /* List of < constraints */
-  IdxScan *pNextScan;             /* Next IdxScan object for same analysis */
-};
-
-/*
-** Information regarding a single database table. Extracted from 
-** "PRAGMA table_info" by function idxGetTableInfo().
-*/
-struct IdxColumn {
-  char *zName;
-  char *zColl;
-  int iPk;
-};
-struct IdxTable {
-  int nCol;
-  char *zName;                    /* Table name */
-  IdxColumn *aCol;
-  IdxTable *pNext;                /* Next table in linked list of all tables */
-};
-
-/*
-** An object of the following type is created for each unique table/write-op
-** seen. The objects are stored in a singly-linked list beginning at
-** sqlite3expert.pWrite.
-*/
-struct IdxWrite {
-  IdxTable *pTab;
-  int eOp;                        /* SQLITE_UPDATE, DELETE or INSERT */
-  IdxWrite *pNext;
-};
-
-/*
-** Each statement being analyzed is represented by an instance of this
-** structure.
-*/
-struct IdxStatement {
-  int iId;                        /* Statement number */
-  char *zSql;                     /* SQL statement */
-  char *zIdx;                     /* Indexes */
-  char *zEQP;                     /* Plan */
-  IdxStatement *pNext;
-};
-
-
-/*
-** A hash table for storing strings. With space for a payload string
-** with each entry. Methods are:
-**
-**   idxHashInit()
-**   idxHashClear()
-**   idxHashAdd()
-**   idxHashSearch()
-*/
-#define IDX_HASH_SIZE 1023
-typedef struct IdxHashEntry IdxHashEntry;
-typedef struct IdxHash IdxHash;
-struct IdxHashEntry {
-  char *zKey;                     /* nul-terminated key */
-  char *zVal;                     /* nul-terminated value string */
-  char *zVal2;                    /* nul-terminated value string 2 */
-  IdxHashEntry *pHashNext;        /* Next entry in same hash bucket */
-  IdxHashEntry *pNext;            /* Next entry in hash */
-};
-struct IdxHash {
-  IdxHashEntry *pFirst;
-  IdxHashEntry *aHash[IDX_HASH_SIZE];
-};
-
-/*
-** sqlite3expert object.
-*/
-struct sqlite3expert {
-  int iSample;                    /* Percentage of tables to sample for stat1 */
-  sqlite3 *db;                    /* User database */
-  sqlite3 *dbm;                   /* In-memory db for this analysis */
-  sqlite3 *dbv;                   /* Vtab schema for this analysis */
-  IdxTable *pTable;               /* List of all IdxTable objects */
-  IdxScan *pScan;                 /* List of scan objects */
-  IdxWrite *pWrite;               /* List of write objects */
-  IdxStatement *pStatement;       /* List of IdxStatement objects */
-  int bRun;                       /* True once analysis has run */
-  char **pzErrmsg;
-  int rc;                         /* Error code from whereinfo hook */
-  IdxHash hIdx;                   /* Hash containing all candidate indexes */
-  char *zCandidates;              /* For EXPERT_REPORT_CANDIDATES */
-};
-
-
-/*
-** Allocate and return nByte bytes of zeroed memory using sqlite3_malloc(). 
-** If the allocation fails, set *pRc to SQLITE_NOMEM and return NULL.
-*/
-static void *idxMalloc(int *pRc, int nByte){
-  void *pRet;
-  assert( *pRc==SQLITE_OK );
-  assert( nByte>0 );
-  pRet = sqlite3_malloc(nByte);
-  if( pRet ){
-    memset(pRet, 0, nByte);
-  }else{
-    *pRc = SQLITE_NOMEM;
-  }
-  return pRet;
-}
-
-/*
-** Initialize an IdxHash hash table.
-*/
-static void idxHashInit(IdxHash *pHash){
-  memset(pHash, 0, sizeof(IdxHash));
-}
-
-/*
-** Reset an IdxHash hash table.
-*/
-static void idxHashClear(IdxHash *pHash){
-  int i;
-  for(i=0; i<IDX_HASH_SIZE; i++){
-    IdxHashEntry *pEntry;
-    IdxHashEntry *pNext;
-    for(pEntry=pHash->aHash[i]; pEntry; pEntry=pNext){
-      pNext = pEntry->pHashNext;
-      sqlite3_free(pEntry->zVal2);
-      sqlite3_free(pEntry);
-    }
-  }
-  memset(pHash, 0, sizeof(IdxHash));
-}
-
-/*
-** Return the index of the hash bucket that the string specified by the
-** arguments to this function belongs.
-*/
-static int idxHashString(const char *z, int n){
-  unsigned int ret = 0;
-  int i;
-  for(i=0; i<n; i++){
-    ret += (ret<<3) + (unsigned char)(z[i]);
-  }
-  return (int)(ret % IDX_HASH_SIZE);
-}
-
-/*
-** If zKey is already present in the hash table, return non-zero and do
-** nothing. Otherwise, add an entry with key zKey and payload string zVal to
-** the hash table passed as the second argument. 
-*/
-static int idxHashAdd(
-  int *pRc, 
-  IdxHash *pHash, 
-  const char *zKey,
-  const char *zVal
-){
-  int nKey = STRLEN(zKey);
-  int iHash = idxHashString(zKey, nKey);
-  int nVal = (zVal ? STRLEN(zVal) : 0);
-  IdxHashEntry *pEntry;
-  assert( iHash>=0 );
-  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
-    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
-      return 1;
-    }
-  }
-  pEntry = idxMalloc(pRc, sizeof(IdxHashEntry) + nKey+1 + nVal+1);
-  if( pEntry ){
-    pEntry->zKey = (char*)&pEntry[1];
-    memcpy(pEntry->zKey, zKey, nKey);
-    if( zVal ){
-      pEntry->zVal = &pEntry->zKey[nKey+1];
-      memcpy(pEntry->zVal, zVal, nVal);
-    }
-    pEntry->pHashNext = pHash->aHash[iHash];
-    pHash->aHash[iHash] = pEntry;
-
-    pEntry->pNext = pHash->pFirst;
-    pHash->pFirst = pEntry;
-  }
-  return 0;
-}
-
-/*
-** If zKey/nKey is present in the hash table, return a pointer to the 
-** hash-entry object.
-*/
-static IdxHashEntry *idxHashFind(IdxHash *pHash, const char *zKey, int nKey){
-  int iHash;
-  IdxHashEntry *pEntry;
-  if( nKey<0 ) nKey = STRLEN(zKey);
-  iHash = idxHashString(zKey, nKey);
-  assert( iHash>=0 );
-  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
-    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
-      return pEntry;
-    }
-  }
-  return 0;
-}
-
-/*
-** If the hash table contains an entry with a key equal to the string
-** passed as the final two arguments to this function, return a pointer
-** to the payload string. Otherwise, if zKey/nKey is not present in the
-** hash table, return NULL.
-*/
-static const char *idxHashSearch(IdxHash *pHash, const char *zKey, int nKey){
-  IdxHashEntry *pEntry = idxHashFind(pHash, zKey, nKey);
-  if( pEntry ) return pEntry->zVal;
-  return 0;
-}
-
-/*
-** Allocate and return a new IdxConstraint object. Set the IdxConstraint.zColl
-** variable to point to a copy of nul-terminated string zColl.
-*/
-static IdxConstraint *idxNewConstraint(int *pRc, const char *zColl){
-  IdxConstraint *pNew;
-  int nColl = STRLEN(zColl);
-
-  assert( *pRc==SQLITE_OK );
-  pNew = (IdxConstraint*)idxMalloc(pRc, sizeof(IdxConstraint) * nColl + 1);
-  if( pNew ){
-    pNew->zColl = (char*)&pNew[1];
-    memcpy(pNew->zColl, zColl, nColl+1);
-  }
-  return pNew;
-}
-
-/*
-** An error associated with database handle db has just occurred. Pass
-** the error message to callback function xOut.
-*/
-static void idxDatabaseError(
-  sqlite3 *db,                    /* Database handle */
-  char **pzErrmsg                 /* Write error here */
-){
-  *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
-}
-
-/*
-** Prepare an SQL statement.
-*/
-static int idxPrepareStmt(
-  sqlite3 *db,                    /* Database handle to compile against */
-  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
-  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
-  const char *zSql                /* SQL statement to compile */
-){
-  int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
-  if( rc!=SQLITE_OK ){
-    *ppStmt = 0;
-    idxDatabaseError(db, pzErrmsg);
-  }
-  return rc;
-}
-
-/*
-** Prepare an SQL statement using the results of a printf() formatting.
-*/
-static int idxPrintfPrepareStmt(
-  sqlite3 *db,                    /* Database handle to compile against */
-  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
-  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
-  const char *zFmt,               /* printf() format of SQL statement */
-  ...                             /* Trailing printf() arguments */
-){
-  va_list ap;
-  int rc;
-  char *zSql;
-  va_start(ap, zFmt);
-  zSql = sqlite3_vmprintf(zFmt, ap);
-  if( zSql==0 ){
-    rc = SQLITE_NOMEM;
-  }else{
-    rc = idxPrepareStmt(db, ppStmt, pzErrmsg, zSql);
-    sqlite3_free(zSql);
-  }
-  va_end(ap);
-  return rc;
-}
-
-
-/*************************************************************************
-** Beginning of virtual table implementation.
-*/
-typedef struct ExpertVtab ExpertVtab;
-struct ExpertVtab {
-  sqlite3_vtab base;
-  IdxTable *pTab;
-  sqlite3expert *pExpert;
-};
-
-typedef struct ExpertCsr ExpertCsr;
-struct ExpertCsr {
-  sqlite3_vtab_cursor base;
-  sqlite3_stmt *pData;
-};
-
-static char *expertDequote(const char *zIn){
-  int n = STRLEN(zIn);
-  char *zRet = sqlite3_malloc(n);
-
-  assert( zIn[0]=='\'' );
-  assert( zIn[n-1]=='\'' );
-
-  if( zRet ){
-    int iOut = 0;
-    int iIn = 0;
-    for(iIn=1; iIn<(n-1); iIn++){
-      if( zIn[iIn]=='\'' ){
-        assert( zIn[iIn+1]=='\'' );
-        iIn++;
-      }
-      zRet[iOut++] = zIn[iIn];
-    }
-    zRet[iOut] = '\0';
-  }
-
-  return zRet;
-}
-
-/* 
-** This function is the implementation of both the xConnect and xCreate
-** methods of the r-tree virtual table.
-**
-**   argv[0]   -> module name
-**   argv[1]   -> database name
-**   argv[2]   -> table name
-**   argv[...] -> column names...
-*/
-static int expertConnect(
-  sqlite3 *db,
-  void *pAux,
-  int argc, const char *const*argv,
-  sqlite3_vtab **ppVtab,
-  char **pzErr
-){
-  sqlite3expert *pExpert = (sqlite3expert*)pAux;
-  ExpertVtab *p = 0;
-  int rc;
-
-  if( argc!=4 ){
-    *pzErr = sqlite3_mprintf("internal error!");
-    rc = SQLITE_ERROR;
-  }else{
-    char *zCreateTable = expertDequote(argv[3]);
-    if( zCreateTable ){
-      rc = sqlite3_declare_vtab(db, zCreateTable);
-      if( rc==SQLITE_OK ){
-        p = idxMalloc(&rc, sizeof(ExpertVtab));
-      }
-      if( rc==SQLITE_OK ){
-        p->pExpert = pExpert;
-        p->pTab = pExpert->pTable;
-        assert( sqlite3_stricmp(p->pTab->zName, argv[2])==0 );
-      }
-      sqlite3_free(zCreateTable);
-    }else{
-      rc = SQLITE_NOMEM;
-    }
-  }
-
-  *ppVtab = (sqlite3_vtab*)p;
-  return rc;
-}
-
-static int expertDisconnect(sqlite3_vtab *pVtab){
-  ExpertVtab *p = (ExpertVtab*)pVtab;
-  sqlite3_free(p);
-  return SQLITE_OK;
-}
-
-static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
-  ExpertVtab *p = (ExpertVtab*)pVtab;
-  int rc = SQLITE_OK;
-  int n = 0;
-  IdxScan *pScan;
-  const int opmask = 
-    SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
-    SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
-    SQLITE_INDEX_CONSTRAINT_LE;
-
-  pScan = idxMalloc(&rc, sizeof(IdxScan));
-  if( pScan ){
-    int i;
-
-    /* Link the new scan object into the list */
-    pScan->pTab = p->pTab;
-    pScan->pNextScan = p->pExpert->pScan;
-    p->pExpert->pScan = pScan;
-
-    /* Add the constraints to the IdxScan object */
-    for(i=0; i<pIdxInfo->nConstraint; i++){
-      struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
-      if( pCons->usable 
-       && pCons->iColumn>=0 
-       && p->pTab->aCol[pCons->iColumn].iPk==0
-       && (pCons->op & opmask) 
-      ){
-        IdxConstraint *pNew;
-        const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
-        pNew = idxNewConstraint(&rc, zColl);
-        if( pNew ){
-          pNew->iCol = pCons->iColumn;
-          if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
-            pNew->pNext = pScan->pEq;
-            pScan->pEq = pNew;
-          }else{
-            pNew->bRange = 1;
-            pNew->pNext = pScan->pRange;
-            pScan->pRange = pNew;
-          }
-        }
-        n++;
-        pIdxInfo->aConstraintUsage[i].argvIndex = n;
-      }
-    }
-
-    /* Add the ORDER BY to the IdxScan object */
-    for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
-      int iCol = pIdxInfo->aOrderBy[i].iColumn;
-      if( iCol>=0 ){
-        IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
-        if( pNew ){
-          pNew->iCol = iCol;
-          pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
-          pNew->pNext = pScan->pOrder;
-          pNew->pLink = pScan->pOrder;
-          pScan->pOrder = pNew;
-          n++;
-        }
-      }
-    }
-  }
-
-  pIdxInfo->estimatedCost = 1000000.0 / (n+1);
-  return rc;
-}
-
-static int expertUpdate(
-  sqlite3_vtab *pVtab, 
-  int nData, 
-  sqlite3_value **azData, 
-  sqlite_int64 *pRowid
-){
-  (void)pVtab;
-  (void)nData;
-  (void)azData;
-  (void)pRowid;
-  return SQLITE_OK;
-}
-
-/* 
-** Virtual table module xOpen method.
-*/
-static int expertOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
-  int rc = SQLITE_OK;
-  ExpertCsr *pCsr;
-  (void)pVTab;
-  pCsr = idxMalloc(&rc, sizeof(ExpertCsr));
-  *ppCursor = (sqlite3_vtab_cursor*)pCsr;
-  return rc;
-}
-
-/* 
-** Virtual table module xClose method.
-*/
-static int expertClose(sqlite3_vtab_cursor *cur){
-  ExpertCsr *pCsr = (ExpertCsr*)cur;
-  sqlite3_finalize(pCsr->pData);
-  sqlite3_free(pCsr);
-  return SQLITE_OK;
-}
-
-/*
-** Virtual table module xEof method.
-**
-** Return non-zero if the cursor does not currently point to a valid 
-** record (i.e if the scan has finished), or zero otherwise.
-*/
-static int expertEof(sqlite3_vtab_cursor *cur){
-  ExpertCsr *pCsr = (ExpertCsr*)cur;
-  return pCsr->pData==0;
-}
-
-/* 
-** Virtual table module xNext method.
-*/
-static int expertNext(sqlite3_vtab_cursor *cur){
-  ExpertCsr *pCsr = (ExpertCsr*)cur;
-  int rc = SQLITE_OK;
-
-  assert( pCsr->pData );
-  rc = sqlite3_step(pCsr->pData);
-  if( rc!=SQLITE_ROW ){
-    rc = sqlite3_finalize(pCsr->pData);
-    pCsr->pData = 0;
-  }else{
-    rc = SQLITE_OK;
-  }
-
-  return rc;
-}
-
-/* 
-** Virtual table module xRowid method.
-*/
-static int expertRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
-  (void)cur;
-  *pRowid = 0;
-  return SQLITE_OK;
-}
-
-/* 
-** Virtual table module xColumn method.
-*/
-static int expertColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
-  ExpertCsr *pCsr = (ExpertCsr*)cur;
-  sqlite3_value *pVal;
-  pVal = sqlite3_column_value(pCsr->pData, i);
-  if( pVal ){
-    sqlite3_result_value(ctx, pVal);
-  }
-  return SQLITE_OK;
-}
-
-/* 
-** Virtual table module xFilter method.
-*/
-static int expertFilter(
-  sqlite3_vtab_cursor *cur, 
-  int idxNum, const char *idxStr,
-  int argc, sqlite3_value **argv
-){
-  ExpertCsr *pCsr = (ExpertCsr*)cur;
-  ExpertVtab *pVtab = (ExpertVtab*)(cur->pVtab);
-  sqlite3expert *pExpert = pVtab->pExpert;
-  int rc;
-
-  (void)idxNum;
-  (void)idxStr;
-  (void)argc;
-  (void)argv;
-  rc = sqlite3_finalize(pCsr->pData);
-  pCsr->pData = 0;
-  if( rc==SQLITE_OK ){
-    rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
-        "SELECT * FROM main.%Q WHERE sample()", pVtab->pTab->zName
-    );
-  }
-
-  if( rc==SQLITE_OK ){
-    rc = expertNext(cur);
-  }
-  return rc;
-}
-
-static int idxRegisterVtab(sqlite3expert *p){
-  static sqlite3_module expertModule = {
-    2,                            /* iVersion */
-    expertConnect,                /* xCreate - create a table */
-    expertConnect,                /* xConnect - connect to an existing table */
-    expertBestIndex,              /* xBestIndex - Determine search strategy */
-    expertDisconnect,             /* xDisconnect - Disconnect from a table */
-    expertDisconnect,             /* xDestroy - Drop a table */
-    expertOpen,                   /* xOpen - open a cursor */
-    expertClose,                  /* xClose - close a cursor */
-    expertFilter,                 /* xFilter - configure scan constraints */
-    expertNext,                   /* xNext - advance a cursor */
-    expertEof,                    /* xEof */
-    expertColumn,                 /* xColumn - read data */
-    expertRowid,                  /* xRowid - read data */
-    expertUpdate,                 /* xUpdate - write data */
-    0,                            /* xBegin - begin transaction */
-    0,                            /* xSync - sync transaction */
-    0,                            /* xCommit - commit transaction */
-    0,                            /* xRollback - rollback transaction */
-    0,                            /* xFindFunction - function overloading */
-    0,                            /* xRename - rename the table */
-    0,                            /* xSavepoint */
-    0,                            /* xRelease */
-    0,                            /* xRollbackTo */
-    0,                            /* xShadowName */
-  };
-
-  return sqlite3_create_module(p->dbv, "expert", &expertModule, (void*)p);
-}
-/*
-** End of virtual table implementation.
-*************************************************************************/
-/*
-** Finalize SQL statement pStmt. If (*pRc) is SQLITE_OK when this function
-** is called, set it to the return value of sqlite3_finalize() before
-** returning. Otherwise, discard the sqlite3_finalize() return value.
-*/
-static void idxFinalize(int *pRc, sqlite3_stmt *pStmt){
-  int rc = sqlite3_finalize(pStmt);
-  if( *pRc==SQLITE_OK ) *pRc = rc;
-}
-
-/*
-** Attempt to allocate an IdxTable structure corresponding to table zTab
-** in the main database of connection db. If successful, set (*ppOut) to
-** point to the new object and return SQLITE_OK. Otherwise, return an
-** SQLite error code and set (*ppOut) to NULL. In this case *pzErrmsg may be
-** set to point to an error string.
-**
-** It is the responsibility of the caller to eventually free either the
-** IdxTable object or error message using sqlite3_free().
-*/
-static int idxGetTableInfo(
-  sqlite3 *db,                    /* Database connection to read details from */
-  const char *zTab,               /* Table name */
-  IdxTable **ppOut,               /* OUT: New object (if successful) */
-  char **pzErrmsg                 /* OUT: Error message (if not) */
-){
-  sqlite3_stmt *p1 = 0;
-  int nCol = 0;
-  int nTab = STRLEN(zTab);
-  int nByte = sizeof(IdxTable) + nTab + 1;
-  IdxTable *pNew = 0;
-  int rc, rc2;
-  char *pCsr = 0;
-  int nPk = 0;
-
-  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_xinfo=%Q", zTab);
-  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
-    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
-    nByte += 1 + STRLEN(zCol);
-    rc = sqlite3_table_column_metadata(
-        db, "main", zTab, zCol, 0, &zCol, 0, 0, 0
-    );
-    nByte += 1 + STRLEN(zCol);
-    nCol++;
-    nPk += (sqlite3_column_int(p1, 5)>0);
-  }
-  rc2 = sqlite3_reset(p1);
-  if( rc==SQLITE_OK ) rc = rc2;
-
-  nByte += sizeof(IdxColumn) * nCol;
-  if( rc==SQLITE_OK ){
-    pNew = idxMalloc(&rc, nByte);
-  }
-  if( rc==SQLITE_OK ){
-    pNew->aCol = (IdxColumn*)&pNew[1];
-    pNew->nCol = nCol;
-    pCsr = (char*)&pNew->aCol[nCol];
-  }
-
-  nCol = 0;
-  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
-    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
-    int nCopy = STRLEN(zCol) + 1;
-    pNew->aCol[nCol].zName = pCsr;
-    pNew->aCol[nCol].iPk = (sqlite3_column_int(p1, 5)==1 && nPk==1);
-    memcpy(pCsr, zCol, nCopy);
-    pCsr += nCopy;
-
-    rc = sqlite3_table_column_metadata(
-        db, "main", zTab, zCol, 0, &zCol, 0, 0, 0
-    );
-    if( rc==SQLITE_OK ){
-      nCopy = STRLEN(zCol) + 1;
-      pNew->aCol[nCol].zColl = pCsr;
-      memcpy(pCsr, zCol, nCopy);
-      pCsr += nCopy;
-    }
-
-    nCol++;
-  }
-  idxFinalize(&rc, p1);
-
-  if( rc!=SQLITE_OK ){
-    sqlite3_free(pNew);
-    pNew = 0;
-  }else{
-    pNew->zName = pCsr;
-    memcpy(pNew->zName, zTab, nTab+1);
-  }
-
-  *ppOut = pNew;
-  return rc;
-}
-
-/*
-** This function is a no-op if *pRc is set to anything other than 
-** SQLITE_OK when it is called.
-**
-** If *pRc is initially set to SQLITE_OK, then the text specified by
-** the printf() style arguments is appended to zIn and the result returned
-** in a buffer allocated by sqlite3_malloc(). sqlite3_free() is called on
-** zIn before returning.
-*/
-static char *idxAppendText(int *pRc, char *zIn, const char *zFmt, ...){
-  va_list ap;
-  char *zAppend = 0;
-  char *zRet = 0;
-  int nIn = zIn ? STRLEN(zIn) : 0;
-  int nAppend = 0;
-  va_start(ap, zFmt);
-  if( *pRc==SQLITE_OK ){
-    zAppend = sqlite3_vmprintf(zFmt, ap);
-    if( zAppend ){
-      nAppend = STRLEN(zAppend);
-      zRet = (char*)sqlite3_malloc(nIn + nAppend + 1);
-    }
-    if( zAppend && zRet ){
-      if( nIn ) memcpy(zRet, zIn, nIn);
-      memcpy(&zRet[nIn], zAppend, nAppend+1);
-    }else{
-      sqlite3_free(zRet);
-      zRet = 0;
-      *pRc = SQLITE_NOMEM;
-    }
-    sqlite3_free(zAppend);
-    sqlite3_free(zIn);
-  }
-  va_end(ap);
-  return zRet;
-}
-
-/*
-** Return true if zId must be quoted in order to use it as an SQL
-** identifier, or false otherwise.
-*/
-static int idxIdentifierRequiresQuotes(const char *zId){
-  int i;
-  for(i=0; zId[i]; i++){
-    if( !(zId[i]=='_')
-     && !(zId[i]>='0' && zId[i]<='9')
-     && !(zId[i]>='a' && zId[i]<='z')
-     && !(zId[i]>='A' && zId[i]<='Z')
-    ){
-      return 1;
-    }
-  }
-  return 0;
-}
-
-/*
-** This function appends an index column definition suitable for constraint
-** pCons to the string passed as zIn and returns the result.
-*/
-static char *idxAppendColDefn(
-  int *pRc,                       /* IN/OUT: Error code */
-  char *zIn,                      /* Column defn accumulated so far */
-  IdxTable *pTab,                 /* Table index will be created on */
-  IdxConstraint *pCons
-){
-  char *zRet = zIn;
-  IdxColumn *p = &pTab->aCol[pCons->iCol];
-  if( zRet ) zRet = idxAppendText(pRc, zRet, ", ");
-
-  if( idxIdentifierRequiresQuotes(p->zName) ){
-    zRet = idxAppendText(pRc, zRet, "%Q", p->zName);
-  }else{
-    zRet = idxAppendText(pRc, zRet, "%s", p->zName);
-  }
-
-  if( sqlite3_stricmp(p->zColl, pCons->zColl) ){
-    if( idxIdentifierRequiresQuotes(pCons->zColl) ){
-      zRet = idxAppendText(pRc, zRet, " COLLATE %Q", pCons->zColl);
-    }else{
-      zRet = idxAppendText(pRc, zRet, " COLLATE %s", pCons->zColl);
-    }
-  }
-
-  if( pCons->bDesc ){
-    zRet = idxAppendText(pRc, zRet, " DESC");
-  }
-  return zRet;
-}
-
-/*
-** Search database dbm for an index compatible with the one idxCreateFromCons()
-** would create from arguments pScan, pEq and pTail. If no error occurs and 
-** such an index is found, return non-zero. Or, if no such index is found,
-** return zero.
-**
-** If an error occurs, set *pRc to an SQLite error code and return zero.
-*/
-static int idxFindCompatible(
-  int *pRc,                       /* OUT: Error code */
-  sqlite3* dbm,                   /* Database to search */
-  IdxScan *pScan,                 /* Scan for table to search for index on */
-  IdxConstraint *pEq,             /* List of == constraints */
-  IdxConstraint *pTail            /* List of range constraints */
-){
-  const char *zTbl = pScan->pTab->zName;
-  sqlite3_stmt *pIdxList = 0;
-  IdxConstraint *pIter;
-  int nEq = 0;                    /* Number of elements in pEq */
-  int rc;
-
-  /* Count the elements in list pEq */
-  for(pIter=pEq; pIter; pIter=pIter->pLink) nEq++;
-
-  rc = idxPrintfPrepareStmt(dbm, &pIdxList, 0, "PRAGMA index_list=%Q", zTbl);
-  while( rc==SQLITE_OK && sqlite3_step(pIdxList)==SQLITE_ROW ){
-    int bMatch = 1;
-    IdxConstraint *pT = pTail;
-    sqlite3_stmt *pInfo = 0;
-    const char *zIdx = (const char*)sqlite3_column_text(pIdxList, 1);
-
-    /* Zero the IdxConstraint.bFlag values in the pEq list */
-    for(pIter=pEq; pIter; pIter=pIter->pLink) pIter->bFlag = 0;
-
-    rc = idxPrintfPrepareStmt(dbm, &pInfo, 0, "PRAGMA index_xInfo=%Q", zIdx);
-    while( rc==SQLITE_OK && sqlite3_step(pInfo)==SQLITE_ROW ){
-      int iIdx = sqlite3_column_int(pInfo, 0);
-      int iCol = sqlite3_column_int(pInfo, 1);
-      const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);
-
-      if( iIdx<nEq ){
-        for(pIter=pEq; pIter; pIter=pIter->pLink){
-          if( pIter->bFlag ) continue;
-          if( pIter->iCol!=iCol ) continue;
-          if( sqlite3_stricmp(pIter->zColl, zColl) ) continue;
-          pIter->bFlag = 1;
-          break;
-        }
-        if( pIter==0 ){
-          bMatch = 0;
-          break;
-        }
-      }else{
-        if( pT ){
-          if( pT->iCol!=iCol || sqlite3_stricmp(pT->zColl, zColl) ){
-            bMatch = 0;
-            break;
-          }
-          pT = pT->pLink;
-        }
-      }
-    }
-    idxFinalize(&rc, pInfo);
-
-    if( rc==SQLITE_OK && bMatch ){
-      sqlite3_finalize(pIdxList);
-      return 1;
-    }
-  }
-  idxFinalize(&rc, pIdxList);
-
-  *pRc = rc;
-  return 0;
-}
-
-static int idxCreateFromCons(
-  sqlite3expert *p,
-  IdxScan *pScan,
-  IdxConstraint *pEq, 
-  IdxConstraint *pTail
-){
-  sqlite3 *dbm = p->dbm;
-  int rc = SQLITE_OK;
-  if( (pEq || pTail) && 0==idxFindCompatible(&rc, dbm, pScan, pEq, pTail) ){
-    IdxTable *pTab = pScan->pTab;
-    char *zCols = 0;
-    char *zIdx = 0;
-    IdxConstraint *pCons;
-    unsigned int h = 0;
-    const char *zFmt;
-
-    for(pCons=pEq; pCons; pCons=pCons->pLink){
-      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
-    }
-    for(pCons=pTail; pCons; pCons=pCons->pLink){
-      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
-    }
-
-    if( rc==SQLITE_OK ){
-      /* Hash the list of columns to come up with a name for the index */
-      const char *zTable = pScan->pTab->zName;
-      char *zName;                /* Index name */
-      int i;
-      for(i=0; zCols[i]; i++){
-        h += ((h<<3) + zCols[i]);
-      }
-      zName = sqlite3_mprintf("%s_idx_%08x", zTable, h);
-      if( zName==0 ){ 
-        rc = SQLITE_NOMEM;
-      }else{
-        if( idxIdentifierRequiresQuotes(zTable) ){
-          zFmt = "CREATE INDEX '%q' ON %Q(%s)";
-        }else{
-          zFmt = "CREATE INDEX %s ON %s(%s)";
-        }
-        zIdx = sqlite3_mprintf(zFmt, zName, zTable, zCols);
-        if( !zIdx ){
-          rc = SQLITE_NOMEM;
-        }else{
-          rc = sqlite3_exec(dbm, zIdx, 0, 0, p->pzErrmsg);
-          idxHashAdd(&rc, &p->hIdx, zName, zIdx);
-        }
-        sqlite3_free(zName);
-        sqlite3_free(zIdx);
-      }
-    }
-
-    sqlite3_free(zCols);
-  }
-  return rc;
-}
-
-/*
-** Return true if list pList (linked by IdxConstraint.pLink) contains
-** a constraint compatible with *p. Otherwise return false.
-*/
-static int idxFindConstraint(IdxConstraint *pList, IdxConstraint *p){
-  IdxConstraint *pCmp;
-  for(pCmp=pList; pCmp; pCmp=pCmp->pLink){
-    if( p->iCol==pCmp->iCol ) return 1;
-  }
-  return 0;
-}
-
-static int idxCreateFromWhere(
-  sqlite3expert *p, 
-  IdxScan *pScan,                 /* Create indexes for this scan */
-  IdxConstraint *pTail            /* range/ORDER BY constraints for inclusion */
-){
-  IdxConstraint *p1 = 0;
-  IdxConstraint *pCon;
-  int rc;
-
-  /* Gather up all the == constraints. */
-  for(pCon=pScan->pEq; pCon; pCon=pCon->pNext){
-    if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
-      pCon->pLink = p1;
-      p1 = pCon;
-    }
-  }
-
-  /* Create an index using the == constraints collected above. And the
-  ** range constraint/ORDER BY terms passed in by the caller, if any. */
-  rc = idxCreateFromCons(p, pScan, p1, pTail);
-
-  /* If no range/ORDER BY passed by the caller, create a version of the
-  ** index for each range constraint.  */
-  if( pTail==0 ){
-    for(pCon=pScan->pRange; rc==SQLITE_OK && pCon; pCon=pCon->pNext){
-      assert( pCon->pLink==0 );
-      if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
-        rc = idxCreateFromCons(p, pScan, p1, pCon);
-      }
-    }
-  }
-
-  return rc;
-}
-
-/*
-** Create candidate indexes in database [dbm] based on the data in 
-** linked-list pScan.
-*/
-static int idxCreateCandidates(sqlite3expert *p){
-  int rc = SQLITE_OK;
-  IdxScan *pIter;
-
-  for(pIter=p->pScan; pIter && rc==SQLITE_OK; pIter=pIter->pNextScan){
-    rc = idxCreateFromWhere(p, pIter, 0);
-    if( rc==SQLITE_OK && pIter->pOrder ){
-      rc = idxCreateFromWhere(p, pIter, pIter->pOrder);
-    }
-  }
-
-  return rc;
-}
-
-/*
-** Free all elements of the linked list starting at pConstraint.
-*/
-static void idxConstraintFree(IdxConstraint *pConstraint){
-  IdxConstraint *pNext;
-  IdxConstraint *p;
-
-  for(p=pConstraint; p; p=pNext){
-    pNext = p->pNext;
-    sqlite3_free(p);
-  }
-}
-
-/*
-** Free all elements of the linked list starting from pScan up until pLast
-** (pLast is not freed).
-*/
-static void idxScanFree(IdxScan *pScan, IdxScan *pLast){
-  IdxScan *p;
-  IdxScan *pNext;
-  for(p=pScan; p!=pLast; p=pNext){
-    pNext = p->pNextScan;
-    idxConstraintFree(p->pOrder);
-    idxConstraintFree(p->pEq);
-    idxConstraintFree(p->pRange);
-    sqlite3_free(p);
-  }
-}
-
-/*
-** Free all elements of the linked list starting from pStatement up 
-** until pLast (pLast is not freed).
-*/
-static void idxStatementFree(IdxStatement *pStatement, IdxStatement *pLast){
-  IdxStatement *p;
-  IdxStatement *pNext;
-  for(p=pStatement; p!=pLast; p=pNext){
-    pNext = p->pNext;
-    sqlite3_free(p->zEQP);
-    sqlite3_free(p->zIdx);
-    sqlite3_free(p);
-  }
-}
-
-/*
-** Free the linked list of IdxTable objects starting at pTab.
-*/
-static void idxTableFree(IdxTable *pTab){
-  IdxTable *pIter;
-  IdxTable *pNext;
-  for(pIter=pTab; pIter; pIter=pNext){
-    pNext = pIter->pNext;
-    sqlite3_free(pIter);
-  }
-}
-
-/*
-** Free the linked list of IdxWrite objects starting at pTab.
-*/
-static void idxWriteFree(IdxWrite *pTab){
-  IdxWrite *pIter;
-  IdxWrite *pNext;
-  for(pIter=pTab; pIter; pIter=pNext){
-    pNext = pIter->pNext;
-    sqlite3_free(pIter);
-  }
-}
-
-
-
-/*
-** This function is called after candidate indexes have been created. It
-** runs all the queries to see which indexes they prefer, and populates
-** IdxStatement.zIdx and IdxStatement.zEQP with the results.
-*/
-int idxFindIndexes(
-  sqlite3expert *p,
-  char **pzErr                         /* OUT: Error message (sqlite3_malloc) */
-){
-  IdxStatement *pStmt;
-  sqlite3 *dbm = p->dbm;
-  int rc = SQLITE_OK;
-
-  IdxHash hIdx;
-  idxHashInit(&hIdx);
-
-  for(pStmt=p->pStatement; rc==SQLITE_OK && pStmt; pStmt=pStmt->pNext){
-    IdxHashEntry *pEntry;
-    sqlite3_stmt *pExplain = 0;
-    idxHashClear(&hIdx);
-    rc = idxPrintfPrepareStmt(dbm, &pExplain, pzErr,
-        "EXPLAIN QUERY PLAN %s", pStmt->zSql
-    );
-    while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
-      /* int iId = sqlite3_column_int(pExplain, 0); */
-      /* int iParent = sqlite3_column_int(pExplain, 1); */
-      /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
-      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
-      int nDetail;
-      int i;
-
-      if( !zDetail ) continue;
-      nDetail = STRLEN(zDetail);
-
-      for(i=0; i<nDetail; i++){
-        const char *zIdx = 0;
-        if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
-          zIdx = &zDetail[i+13];
-        }else if( i+22<nDetail 
-            && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 
-        ){
-          zIdx = &zDetail[i+22];
-        }
-        if( zIdx ){
-          const char *zSql;
-          int nIdx = 0;
-          while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
-            nIdx++;
-          }
-          zSql = idxHashSearch(&p->hIdx, zIdx, nIdx);
-          if( zSql ){
-            idxHashAdd(&rc, &hIdx, zSql, 0);
-            if( rc ) goto find_indexes_out;
-          }
-          break;
-        }
-      }
-
-      if( zDetail[0]!='-' ){
-        pStmt->zEQP = idxAppendText(&rc, pStmt->zEQP, "%s\n", zDetail);
-      }
-    }
-
-    for(pEntry=hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
-      pStmt->zIdx = idxAppendText(&rc, pStmt->zIdx, "%s;\n", pEntry->zKey);
-    }
-
-    idxFinalize(&rc, pExplain);
-  }
-
- find_indexes_out:
-  idxHashClear(&hIdx);
-  return rc;
-}
-
-static int idxAuthCallback(
-  void *pCtx,
-  int eOp,
-  const char *z3,
-  const char *z4,
-  const char *zDb,
-  const char *zTrigger
-){
-  int rc = SQLITE_OK;
-  (void)z4;
-  (void)zTrigger;
-  if( eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE || eOp==SQLITE_DELETE ){
-    if( sqlite3_stricmp(zDb, "main")==0 ){
-      sqlite3expert *p = (sqlite3expert*)pCtx;
-      IdxTable *pTab;
-      for(pTab=p->pTable; pTab; pTab=pTab->pNext){
-        if( 0==sqlite3_stricmp(z3, pTab->zName) ) break;
-      }
-      if( pTab ){
-        IdxWrite *pWrite;
-        for(pWrite=p->pWrite; pWrite; pWrite=pWrite->pNext){
-          if( pWrite->pTab==pTab && pWrite->eOp==eOp ) break;
-        }
-        if( pWrite==0 ){
-          pWrite = idxMalloc(&rc, sizeof(IdxWrite));
-          if( rc==SQLITE_OK ){
-            pWrite->pTab = pTab;
-            pWrite->eOp = eOp;
-            pWrite->pNext = p->pWrite;
-            p->pWrite = pWrite;
-          }
-        }
-      }
-    }
-  }
-  return rc;
-}
-
-static int idxProcessOneTrigger(
-  sqlite3expert *p, 
-  IdxWrite *pWrite, 
-  char **pzErr
-){
-  static const char *zInt = UNIQUE_TABLE_NAME;
-  static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
-  IdxTable *pTab = pWrite->pTab;
-  const char *zTab = pTab->zName;
-  const char *zSql = 
-    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
-    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
-    "ORDER BY type;";
-  sqlite3_stmt *pSelect = 0;
-  int rc = SQLITE_OK;
-  char *zWrite = 0;
-
-  /* Create the table and its triggers in the temp schema */
-  rc = idxPrintfPrepareStmt(p->db, &pSelect, pzErr, zSql, zTab, zTab);
-  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSelect) ){
-    const char *zCreate = (const char*)sqlite3_column_text(pSelect, 0);
-    rc = sqlite3_exec(p->dbv, zCreate, 0, 0, pzErr);
-  }
-  idxFinalize(&rc, pSelect);
-
-  /* Rename the table in the temp schema to zInt */
-  if( rc==SQLITE_OK ){
-    char *z = sqlite3_mprintf("ALTER TABLE temp.%Q RENAME TO %Q", zTab, zInt);
-    if( z==0 ){
-      rc = SQLITE_NOMEM;
-    }else{
-      rc = sqlite3_exec(p->dbv, z, 0, 0, pzErr);
-      sqlite3_free(z);
-    }
-  }
-
-  switch( pWrite->eOp ){
-    case SQLITE_INSERT: {
-      int i;
-      zWrite = idxAppendText(&rc, zWrite, "INSERT INTO %Q VALUES(", zInt);
-      for(i=0; i<pTab->nCol; i++){
-        zWrite = idxAppendText(&rc, zWrite, "%s?", i==0 ? "" : ", ");
-      }
-      zWrite = idxAppendText(&rc, zWrite, ")");
-      break;
-    }
-    case SQLITE_UPDATE: {
-      int i;
-      zWrite = idxAppendText(&rc, zWrite, "UPDATE %Q SET ", zInt);
-      for(i=0; i<pTab->nCol; i++){
-        zWrite = idxAppendText(&rc, zWrite, "%s%Q=?", i==0 ? "" : ", ", 
-            pTab->aCol[i].zName
-        );
-      }
-      break;
-    }
-    default: {
-      assert( pWrite->eOp==SQLITE_DELETE );
-      if( rc==SQLITE_OK ){
-        zWrite = sqlite3_mprintf("DELETE FROM %Q", zInt);
-        if( zWrite==0 ) rc = SQLITE_NOMEM;
-      }
-    }
-  }
-
-  if( rc==SQLITE_OK ){
-    sqlite3_stmt *pX = 0;
-    rc = sqlite3_prepare_v2(p->dbv, zWrite, -1, &pX, 0);
-    idxFinalize(&rc, pX);
-    if( rc!=SQLITE_OK ){
-      idxDatabaseError(p->dbv, pzErr);
-    }
-  }
-  sqlite3_free(zWrite);
-
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_exec(p->dbv, zDrop, 0, 0, pzErr);
-  }
-
-  return rc;
-}
-
-static int idxProcessTriggers(sqlite3expert *p, char **pzErr){
-  int rc = SQLITE_OK;
-  IdxWrite *pEnd = 0;
-  IdxWrite *pFirst = p->pWrite;
-
-  while( rc==SQLITE_OK && pFirst!=pEnd ){
-    IdxWrite *pIter;
-    for(pIter=pFirst; rc==SQLITE_OK && pIter!=pEnd; pIter=pIter->pNext){
-      rc = idxProcessOneTrigger(p, pIter, pzErr);
-    }
-    pEnd = pFirst;
-    pFirst = p->pWrite;
-  }
-
-  return rc;
-}
-
-
-static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
-  int rc = idxRegisterVtab(p);
-  sqlite3_stmt *pSchema = 0;
-
-  /* For each table in the main db schema:
-  **
-  **   1) Add an entry to the p->pTable list, and
-  **   2) Create the equivalent virtual table in dbv.
-  */
-  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
-      "SELECT type, name, sql, 1 FROM sqlite_schema "
-      "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%%' "
-      " UNION ALL "
-      "SELECT type, name, sql, 2 FROM sqlite_schema "
-      "WHERE type = 'trigger'"
-      "  AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
-      "ORDER BY 4, 1"
-  );
-  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
-    const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
-    const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
-    const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);
-
-    if( zType[0]=='v' || zType[1]=='r' ){
-      rc = sqlite3_exec(p->dbv, zSql, 0, 0, pzErrmsg);
-    }else{
-      IdxTable *pTab;
-      rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
-      if( rc==SQLITE_OK ){
-        int i;
-        char *zInner = 0;
-        char *zOuter = 0;
-        pTab->pNext = p->pTable;
-        p->pTable = pTab;
-
-        /* The statement the vtab will pass to sqlite3_declare_vtab() */
-        zInner = idxAppendText(&rc, 0, "CREATE TABLE x(");
-        for(i=0; i<pTab->nCol; i++){
-          zInner = idxAppendText(&rc, zInner, "%s%Q COLLATE %s", 
-              (i==0 ? "" : ", "), pTab->aCol[i].zName, pTab->aCol[i].zColl
-          );
-        }
-        zInner = idxAppendText(&rc, zInner, ")");
-
-        /* The CVT statement to create the vtab */
-        zOuter = idxAppendText(&rc, 0, 
-            "CREATE VIRTUAL TABLE %Q USING expert(%Q)", zName, zInner
-        );
-        if( rc==SQLITE_OK ){
-          rc = sqlite3_exec(p->dbv, zOuter, 0, 0, pzErrmsg);
-        }
-        sqlite3_free(zInner);
-        sqlite3_free(zOuter);
-      }
-    }
-  }
-  idxFinalize(&rc, pSchema);
-  return rc;
-}
-
-struct IdxSampleCtx {
-  int iTarget;
-  double target;                  /* Target nRet/nRow value */
-  double nRow;                    /* Number of rows seen */
-  double nRet;                    /* Number of rows returned */
-};
-
-static void idxSampleFunc(
-  sqlite3_context *pCtx,
-  int argc,
-  sqlite3_value **argv
-){
-  struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx);
-  int bRet;
-
-  (void)argv;
-  assert( argc==0 );
-  if( p->nRow==0.0 ){
-    bRet = 1;
-  }else{
-    bRet = (p->nRet / p->nRow) <= p->target;
-    if( bRet==0 ){
-      unsigned short rnd;
-      sqlite3_randomness(2, (void*)&rnd);
-      bRet = ((int)rnd % 100) <= p->iTarget;
-    }
-  }
-
-  sqlite3_result_int(pCtx, bRet);
-  p->nRow += 1.0;
-  p->nRet += (double)bRet;
-}
-
-struct IdxRemCtx {
-  int nSlot;
-  struct IdxRemSlot {
-    int eType;                    /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */
-    i64 iVal;                     /* SQLITE_INTEGER value */
-    double rVal;                  /* SQLITE_FLOAT value */
-    int nByte;                    /* Bytes of space allocated at z */
-    int n;                        /* Size of buffer z */
-    char *z;                      /* SQLITE_TEXT/BLOB value */
-  } aSlot[1];
-};
-
-/*
-** Implementation of scalar function rem().
-*/
-static void idxRemFunc(
-  sqlite3_context *pCtx,
-  int argc,
-  sqlite3_value **argv
-){
-  struct IdxRemCtx *p = (struct IdxRemCtx*)sqlite3_user_data(pCtx);
-  struct IdxRemSlot *pSlot;
-  int iSlot;
-  assert( argc==2 );
-
-  iSlot = sqlite3_value_int(argv[0]);
-  assert( iSlot<=p->nSlot );
-  pSlot = &p->aSlot[iSlot];
-
-  switch( pSlot->eType ){
-    case SQLITE_NULL:
-      /* no-op */
-      break;
-
-    case SQLITE_INTEGER:
-      sqlite3_result_int64(pCtx, pSlot->iVal);
-      break;
-
-    case SQLITE_FLOAT:
-      sqlite3_result_double(pCtx, pSlot->rVal);
-      break;
-
-    case SQLITE_BLOB:
-      sqlite3_result_blob(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
-      break;
-
-    case SQLITE_TEXT:
-      sqlite3_result_text(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
-      break;
-  }
-
-  pSlot->eType = sqlite3_value_type(argv[1]);
-  switch( pSlot->eType ){
-    case SQLITE_NULL:
-      /* no-op */
-      break;
-
-    case SQLITE_INTEGER:
-      pSlot->iVal = sqlite3_value_int64(argv[1]);
-      break;
-
-    case SQLITE_FLOAT:
-      pSlot->rVal = sqlite3_value_double(argv[1]);
-      break;
-
-    case SQLITE_BLOB:
-    case SQLITE_TEXT: {
-      int nByte = sqlite3_value_bytes(argv[1]);
-      if( nByte>pSlot->nByte ){
-        char *zNew = (char*)sqlite3_realloc(pSlot->z, nByte*2);
-        if( zNew==0 ){
-          sqlite3_result_error_nomem(pCtx);
-          return;
-        }
-        pSlot->nByte = nByte*2;
-        pSlot->z = zNew;
-      }
-      pSlot->n = nByte;
-      if( pSlot->eType==SQLITE_BLOB ){
-        memcpy(pSlot->z, sqlite3_value_blob(argv[1]), nByte);
-      }else{
-        memcpy(pSlot->z, sqlite3_value_text(argv[1]), nByte);
-      }
-      break;
-    }
-  }
-}
-
-static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
-  int rc = SQLITE_OK;
-  const char *zMax = 
-    "SELECT max(i.seqno) FROM "
-    "  sqlite_schema AS s, "
-    "  pragma_index_list(s.name) AS l, "
-    "  pragma_index_info(l.name) AS i "
-    "WHERE s.type = 'table'";
-  sqlite3_stmt *pMax = 0;
-
-  *pnMax = 0;
-  rc = idxPrepareStmt(db, &pMax, pzErr, zMax);
-  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
-    *pnMax = sqlite3_column_int(pMax, 0) + 1;
-  }
-  idxFinalize(&rc, pMax);
-
-  return rc;
-}
-
-static int idxPopulateOneStat1(
-  sqlite3expert *p,
-  sqlite3_stmt *pIndexXInfo,
-  sqlite3_stmt *pWriteStat,
-  const char *zTab,
-  const char *zIdx,
-  char **pzErr
-){
-  char *zCols = 0;
-  char *zOrder = 0;
-  char *zQuery = 0;
-  int nCol = 0;
-  int i;
-  sqlite3_stmt *pQuery = 0;
-  int *aStat = 0;
-  int rc = SQLITE_OK;
-
-  assert( p->iSample>0 );
-
-  /* Formulate the query text */
-  sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC);
-  while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){
-    const char *zComma = zCols==0 ? "" : ", ";
-    const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
-    const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
-    zCols = idxAppendText(&rc, zCols, 
-        "%sx.%Q IS rem(%d, x.%Q) COLLATE %s", zComma, zName, nCol, zName, zColl
-    );
-    zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
-  }
-  sqlite3_reset(pIndexXInfo);
-  if( rc==SQLITE_OK ){
-    if( p->iSample==100 ){
-      zQuery = sqlite3_mprintf(
-          "SELECT %s FROM %Q x ORDER BY %s", zCols, zTab, zOrder
-      );
-    }else{
-      zQuery = sqlite3_mprintf(
-          "SELECT %s FROM temp."UNIQUE_TABLE_NAME" x ORDER BY %s", zCols, zOrder
-      );
-    }
-  }
-  sqlite3_free(zCols);
-  sqlite3_free(zOrder);
-
-  /* Formulate the query text */
-  if( rc==SQLITE_OK ){
-    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
-    rc = idxPrepareStmt(dbrem, &pQuery, pzErr, zQuery);
-  }
-  sqlite3_free(zQuery);
-
-  if( rc==SQLITE_OK ){
-    aStat = (int*)idxMalloc(&rc, sizeof(int)*(nCol+1));
-  }
-  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
-    IdxHashEntry *pEntry;
-    char *zStat = 0;
-    for(i=0; i<=nCol; i++) aStat[i] = 1;
-    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
-      aStat[0]++;
-      for(i=0; i<nCol; i++){
-        if( sqlite3_column_int(pQuery, i)==0 ) break;
-      }
-      for(/*no-op*/; i<nCol; i++){
-        aStat[i+1]++;
-      }
-    }
-
-    if( rc==SQLITE_OK ){
-      int s0 = aStat[0];
-      zStat = sqlite3_mprintf("%d", s0);
-      if( zStat==0 ) rc = SQLITE_NOMEM;
-      for(i=1; rc==SQLITE_OK && i<=nCol; i++){
-        zStat = idxAppendText(&rc, zStat, " %d", (s0+aStat[i]/2) / aStat[i]);
-      }
-    }
-
-    if( rc==SQLITE_OK ){
-      sqlite3_bind_text(pWriteStat, 1, zTab, -1, SQLITE_STATIC);
-      sqlite3_bind_text(pWriteStat, 2, zIdx, -1, SQLITE_STATIC);
-      sqlite3_bind_text(pWriteStat, 3, zStat, -1, SQLITE_STATIC);
-      sqlite3_step(pWriteStat);
-      rc = sqlite3_reset(pWriteStat);
-    }
-
-    pEntry = idxHashFind(&p->hIdx, zIdx, STRLEN(zIdx));
-    if( pEntry ){
-      assert( pEntry->zVal2==0 );
-      pEntry->zVal2 = zStat;
-    }else{
-      sqlite3_free(zStat);
-    }
-  }
-  sqlite3_free(aStat);
-  idxFinalize(&rc, pQuery);
-
-  return rc;
-}
-
-static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){
-  int rc;
-  char *zSql;
-
-  rc = sqlite3_exec(p->dbv,"DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
-  if( rc!=SQLITE_OK ) return rc;
-
-  zSql = sqlite3_mprintf(
-      "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q", zTab
-  );
-  if( zSql==0 ) return SQLITE_NOMEM;
-  rc = sqlite3_exec(p->dbv, zSql, 0, 0, 0);
-  sqlite3_free(zSql);
-
-  return rc;
-}
-
-/*
-** This function is called as part of sqlite3_expert_analyze(). Candidate
-** indexes have already been created in database sqlite3expert.dbm, this
-** function populates sqlite_stat1 table in the same database.
-**
-** The stat1 data is generated by querying the 
-*/
-static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
-  int rc = SQLITE_OK;
-  int nMax =0;
-  struct IdxRemCtx *pCtx = 0;
-  struct IdxSampleCtx samplectx; 
-  int i;
-  i64 iPrev = -100000;
-  sqlite3_stmt *pAllIndex = 0;
-  sqlite3_stmt *pIndexXInfo = 0;
-  sqlite3_stmt *pWrite = 0;
-
-  const char *zAllIndex =
-    "SELECT s.rowid, s.name, l.name FROM "
-    "  sqlite_schema AS s, "
-    "  pragma_index_list(s.name) AS l "
-    "WHERE s.type = 'table'";
-  const char *zIndexXInfo = 
-    "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
-  const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";
-
-  /* If iSample==0, no sqlite_stat1 data is required. */
-  if( p->iSample==0 ) return SQLITE_OK;
-
-  rc = idxLargestIndex(p->dbm, &nMax, pzErr);
-  if( nMax<=0 || rc!=SQLITE_OK ) return rc;
-
-  rc = sqlite3_exec(p->dbm, "ANALYZE; PRAGMA writable_schema=1", 0, 0, 0);
-
-  if( rc==SQLITE_OK ){
-    int nByte = sizeof(struct IdxRemCtx) + (sizeof(struct IdxRemSlot) * nMax);
-    pCtx = (struct IdxRemCtx*)idxMalloc(&rc, nByte);
-  }
-
-  if( rc==SQLITE_OK ){
-    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
-    rc = sqlite3_create_function(
-        dbrem, "rem", 2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
-    );
-  }
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_create_function(
-        p->db, "sample", 0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
-    );
-  }
-
-  if( rc==SQLITE_OK ){
-    pCtx->nSlot = nMax+1;
-    rc = idxPrepareStmt(p->dbm, &pAllIndex, pzErr, zAllIndex);
-  }
-  if( rc==SQLITE_OK ){
-    rc = idxPrepareStmt(p->dbm, &pIndexXInfo, pzErr, zIndexXInfo);
-  }
-  if( rc==SQLITE_OK ){
-    rc = idxPrepareStmt(p->dbm, &pWrite, pzErr, zWrite);
-  }
-
-  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pAllIndex) ){
-    i64 iRowid = sqlite3_column_int64(pAllIndex, 0);
-    const char *zTab = (const char*)sqlite3_column_text(pAllIndex, 1);
-    const char *zIdx = (const char*)sqlite3_column_text(pAllIndex, 2);
-    if( p->iSample<100 && iPrev!=iRowid ){
-      samplectx.target = (double)p->iSample / 100.0;
-      samplectx.iTarget = p->iSample;
-      samplectx.nRow = 0.0;
-      samplectx.nRet = 0.0;
-      rc = idxBuildSampleTable(p, zTab);
-      if( rc!=SQLITE_OK ) break;
-    }
-    rc = idxPopulateOneStat1(p, pIndexXInfo, pWrite, zTab, zIdx, pzErr);
-    iPrev = iRowid;
-  }
-  if( rc==SQLITE_OK && p->iSample<100 ){
-    rc = sqlite3_exec(p->dbv, 
-        "DROP TABLE IF EXISTS temp." UNIQUE_TABLE_NAME, 0,0,0
-    );
-  }
-
-  idxFinalize(&rc, pAllIndex);
-  idxFinalize(&rc, pIndexXInfo);
-  idxFinalize(&rc, pWrite);
-
-  if( pCtx ){
-    for(i=0; i<pCtx->nSlot; i++){
-      sqlite3_free(pCtx->aSlot[i].z);
-    }
-    sqlite3_free(pCtx);
-  }
-
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
-  }
-
-  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
-  return rc;
-}
-
-/*
-** Allocate a new sqlite3expert object.
-*/
-sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
-  int rc = SQLITE_OK;
-  sqlite3expert *pNew;
-
-  pNew = (sqlite3expert*)idxMalloc(&rc, sizeof(sqlite3expert));
-
-  /* Open two in-memory databases to work with. The "vtab database" (dbv)
-  ** will contain a virtual table corresponding to each real table in
-  ** the user database schema, and a copy of each view. It is used to
-  ** collect information regarding the WHERE, ORDER BY and other clauses
-  ** of the user's query.
-  */
-  if( rc==SQLITE_OK ){
-    pNew->db = db;
-    pNew->iSample = 100;
-    rc = sqlite3_open(":memory:", &pNew->dbv);
-  }
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_open(":memory:", &pNew->dbm);
-    if( rc==SQLITE_OK ){
-      sqlite3_db_config(pNew->dbm, SQLITE_DBCONFIG_TRIGGER_EQP, 1, (int*)0);
-    }
-  }
-  
-
-  /* Copy the entire schema of database [db] into [dbm]. */
-  if( rc==SQLITE_OK ){
-    sqlite3_stmt *pSql;
-    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
-        "SELECT sql FROM sqlite_schema WHERE name NOT LIKE 'sqlite_%%'"
-        " AND sql NOT LIKE 'CREATE VIRTUAL %%'"
-    );
-    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
-      const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
-      rc = sqlite3_exec(pNew->dbm, zSql, 0, 0, pzErrmsg);
-    }
-    idxFinalize(&rc, pSql);
-  }
-
-  /* Create the vtab schema */
-  if( rc==SQLITE_OK ){
-    rc = idxCreateVtabSchema(pNew, pzErrmsg);
-  }
-
-  /* Register the auth callback with dbv */
-  if( rc==SQLITE_OK ){
-    sqlite3_set_authorizer(pNew->dbv, idxAuthCallback, (void*)pNew);
-  }
-
-  /* If an error has occurred, free the new object and reutrn NULL. Otherwise,
-  ** return the new sqlite3expert handle.  */
-  if( rc!=SQLITE_OK ){
-    sqlite3_expert_destroy(pNew);
-    pNew = 0;
-  }
-  return pNew;
-}
-
-/*
-** Configure an sqlite3expert object.
-*/
-int sqlite3_expert_config(sqlite3expert *p, int op, ...){
-  int rc = SQLITE_OK;
-  va_list ap;
-  va_start(ap, op);
-  switch( op ){
-    case EXPERT_CONFIG_SAMPLE: {
-      int iVal = va_arg(ap, int);
-      if( iVal<0 ) iVal = 0;
-      if( iVal>100 ) iVal = 100;
-      p->iSample = iVal;
-      break;
-    }
-    default:
-      rc = SQLITE_NOTFOUND;
-      break;
-  }
-
-  va_end(ap);
-  return rc;
-}
-
-/*
-** Add an SQL statement to the analysis.
-*/
-int sqlite3_expert_sql(
-  sqlite3expert *p,               /* From sqlite3_expert_new() */
-  const char *zSql,               /* SQL statement to add */
-  char **pzErr                    /* OUT: Error message (if any) */
-){
-  IdxScan *pScanOrig = p->pScan;
-  IdxStatement *pStmtOrig = p->pStatement;
-  int rc = SQLITE_OK;
-  const char *zStmt = zSql;
-
-  if( p->bRun ) return SQLITE_MISUSE;
-
-  while( rc==SQLITE_OK && zStmt && zStmt[0] ){
-    sqlite3_stmt *pStmt = 0;
-    rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
-    if( rc==SQLITE_OK ){
-      if( pStmt ){
-        IdxStatement *pNew;
-        const char *z = sqlite3_sql(pStmt);
-        int n = STRLEN(z);
-        pNew = (IdxStatement*)idxMalloc(&rc, sizeof(IdxStatement) + n+1);
-        if( rc==SQLITE_OK ){
-          pNew->zSql = (char*)&pNew[1];
-          memcpy(pNew->zSql, z, n+1);
-          pNew->pNext = p->pStatement;
-          if( p->pStatement ) pNew->iId = p->pStatement->iId+1;
-          p->pStatement = pNew;
-        }
-        sqlite3_finalize(pStmt);
-      }
-    }else{
-      idxDatabaseError(p->dbv, pzErr);
-    }
-  }
-
-  if( rc!=SQLITE_OK ){
-    idxScanFree(p->pScan, pScanOrig);
-    idxStatementFree(p->pStatement, pStmtOrig);
-    p->pScan = pScanOrig;
-    p->pStatement = pStmtOrig;
-  }
-
-  return rc;
-}
-
-int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr){
-  int rc;
-  IdxHashEntry *pEntry;
-
-  /* Do trigger processing to collect any extra IdxScan structures */
-  rc = idxProcessTriggers(p, pzErr);
-
-  /* Create candidate indexes within the in-memory database file */
-  if( rc==SQLITE_OK ){
-    rc = idxCreateCandidates(p);
-  }
-
-  /* Generate the stat1 data */
-  if( rc==SQLITE_OK ){
-    rc = idxPopulateStat1(p, pzErr);
-  }
-
-  /* Formulate the EXPERT_REPORT_CANDIDATES text */
-  for(pEntry=p->hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
-    p->zCandidates = idxAppendText(&rc, p->zCandidates, 
-        "%s;%s%s\n", pEntry->zVal, 
-        pEntry->zVal2 ? " -- stat1: " : "", pEntry->zVal2
-    );
-  }
-
-  /* Figure out which of the candidate indexes are preferred by the query
-  ** planner and report the results to the user.  */
-  if( rc==SQLITE_OK ){
-    rc = idxFindIndexes(p, pzErr);
-  }
-
-  if( rc==SQLITE_OK ){
-    p->bRun = 1;
-  }
-  return rc;
-}
-
-/*
-** Return the total number of statements that have been added to this
-** sqlite3expert using sqlite3_expert_sql().
-*/
-int sqlite3_expert_count(sqlite3expert *p){
-  int nRet = 0;
-  if( p->pStatement ) nRet = p->pStatement->iId+1;
-  return nRet;
-}
-
-/*
-** Return a component of the report.
-*/
-const char *sqlite3_expert_report(sqlite3expert *p, int iStmt, int eReport){
-  const char *zRet = 0;
-  IdxStatement *pStmt;
-
-  if( p->bRun==0 ) return 0;
-  for(pStmt=p->pStatement; pStmt && pStmt->iId!=iStmt; pStmt=pStmt->pNext);
-  switch( eReport ){
-    case EXPERT_REPORT_SQL:
-      if( pStmt ) zRet = pStmt->zSql;
-      break;
-    case EXPERT_REPORT_INDEXES:
-      if( pStmt ) zRet = pStmt->zIdx;
-      break;
-    case EXPERT_REPORT_PLAN:
-      if( pStmt ) zRet = pStmt->zEQP;
-      break;
-    case EXPERT_REPORT_CANDIDATES:
-      zRet = p->zCandidates;
-      break;
-  }
-  return zRet;
-}
-
-/*
-** Free an sqlite3expert object.
-*/
-void sqlite3_expert_destroy(sqlite3expert *p){
-  if( p ){
-    sqlite3_close(p->dbm);
-    sqlite3_close(p->dbv);
-    idxScanFree(p->pScan, 0);
-    idxStatementFree(p->pStatement, 0);
-    idxTableFree(p->pTable);
-    idxWriteFree(p->pWrite);
-    idxHashClear(&p->hIdx);
-    sqlite3_free(p->zCandidates);
-    sqlite3_free(p);
-  }
-}
-
-#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
diff --git a/ext/expert/sqlite3expert.h b/ext/expert/sqlite3expert.h
deleted file mode 100644
index 6048137237a2..000000000000
--- a/ext/expert/sqlite3expert.h
+++ /dev/null
@@ -1,168 +0,0 @@
-/*
-** 2017 April 07
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-*/
-#if !defined(SQLITEEXPERT_H)
-#define SQLITEEXPERT_H 1
-#include "sqlite3.h"
-
-typedef struct sqlite3expert sqlite3expert;
-
-/*
-** Create a new sqlite3expert object.
-**
-** If successful, a pointer to the new object is returned and (*pzErr) set
-** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to
-** an English-language error message. In this case it is the responsibility
-** of the caller to eventually free the error message buffer using
-** sqlite3_free().
-*/
-sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr);
-
-/*
-** Configure an sqlite3expert object.
-**
-** EXPERT_CONFIG_SAMPLE:
-**   By default, sqlite3_expert_analyze() generates sqlite_stat1 data for
-**   each candidate index. This involves scanning and sorting the entire
-**   contents of each user database table once for each candidate index
-**   associated with the table. For large databases, this can be 
-**   prohibitively slow. This option allows the sqlite3expert object to
-**   be configured so that sqlite_stat1 data is instead generated based on a
-**   subset of each table, or so that no sqlite_stat1 data is used at all.
-**
-**   A single integer argument is passed to this option. If the value is less
-**   than or equal to zero, then no sqlite_stat1 data is generated or used by
-**   the analysis - indexes are recommended based on the database schema only.
-**   Or, if the value is 100 or greater, complete sqlite_stat1 data is
-**   generated for each candidate index (this is the default). Finally, if the
-**   value falls between 0 and 100, then it represents the percentage of user
-**   table rows that should be considered when generating sqlite_stat1 data.
-**
-**   Examples:
-**
-**     // Do not generate any sqlite_stat1 data
-**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0);
-**
-**     // Generate sqlite_stat1 data based on 10% of the rows in each table.
-**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10);
-*/
-int sqlite3_expert_config(sqlite3expert *p, int op, ...);
-
-#define EXPERT_CONFIG_SAMPLE 1    /* int */
-
-/*
-** Specify zero or more SQL statements to be included in the analysis.
-**
-** Buffer zSql must contain zero or more complete SQL statements. This
-** function parses all statements contained in the buffer and adds them
-** to the internal list of statements to analyze. If successful, SQLITE_OK
-** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example
-** due to a error in the SQL - an SQLite error code is returned and (*pzErr)
-** may be set to point to an English language error message. In this case
-** the caller is responsible for eventually freeing the error message buffer
-** using sqlite3_free().
-**
-** If an error does occur while processing one of the statements in the
-** buffer passed as the second argument, none of the statements in the
-** buffer are added to the analysis.
-**
-** This function must be called before sqlite3_expert_analyze(). If a call
-** to this function is made on an sqlite3expert object that has already
-** been passed to sqlite3_expert_analyze() SQLITE_MISUSE is returned
-** immediately and no statements are added to the analysis.
-*/
-int sqlite3_expert_sql(
-  sqlite3expert *p,               /* From a successful sqlite3_expert_new() */
-  const char *zSql,               /* SQL statement(s) to add */
-  char **pzErr                    /* OUT: Error message (if any) */
-);
-
-
-/*
-** This function is called after the sqlite3expert object has been configured
-** with all SQL statements using sqlite3_expert_sql() to actually perform
-** the analysis. Once this function has been called, it is not possible to
-** add further SQL statements to the analysis.
-**
-** If successful, SQLITE_OK is returned and (*pzErr) is set to NULL. Or, if
-** an error occurs, an SQLite error code is returned and (*pzErr) set to 
-** point to a buffer containing an English language error message. In this
-** case it is the responsibility of the caller to eventually free the buffer
-** using sqlite3_free().
-**
-** If an error does occur within this function, the sqlite3expert object
-** is no longer useful for any purpose. At that point it is no longer
-** possible to add further SQL statements to the object or to re-attempt
-** the analysis. The sqlite3expert object must still be freed using a call
-** sqlite3_expert_destroy().
-*/
-int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr);
-
-/*
-** Return the total number of statements loaded using sqlite3_expert_sql().
-** The total number of SQL statements may be different from the total number
-** to calls to sqlite3_expert_sql().
-*/
-int sqlite3_expert_count(sqlite3expert*);
-
-/*
-** Return a component of the report.
-**
-** This function is called after sqlite3_expert_analyze() to extract the
-** results of the analysis. Each call to this function returns either a
-** NULL pointer or a pointer to a buffer containing a nul-terminated string.
-** The value passed as the third argument must be one of the EXPERT_REPORT_*
-** #define constants defined below.
-**
-** For some EXPERT_REPORT_* parameters, the buffer returned contains 
-** information relating to a specific SQL statement. In these cases that
-** SQL statement is identified by the value passed as the second argument.
-** SQL statements are numbered from 0 in the order in which they are parsed.
-** If an out-of-range value (less than zero or equal to or greater than the
-** value returned by sqlite3_expert_count()) is passed as the second argument
-** along with such an EXPERT_REPORT_* parameter, NULL is always returned.
-**
-** EXPERT_REPORT_SQL:
-**   Return the text of SQL statement iStmt.
-**
-** EXPERT_REPORT_INDEXES:
-**   Return a buffer containing the CREATE INDEX statements for all recommended
-**   indexes for statement iStmt. If there are no new recommeded indexes, NULL 
-**   is returned.
-**
-** EXPERT_REPORT_PLAN:
-**   Return a buffer containing the EXPLAIN QUERY PLAN output for SQL query
-**   iStmt after the proposed indexes have been added to the database schema.
-**
-** EXPERT_REPORT_CANDIDATES:
-**   Return a pointer to a buffer containing the CREATE INDEX statements 
-**   for all indexes that were tested (for all SQL statements). The iStmt
-**   parameter is ignored for EXPERT_REPORT_CANDIDATES calls.
-*/
-const char *sqlite3_expert_report(sqlite3expert*, int iStmt, int eReport);
-
-/*
-** Values for the third argument passed to sqlite3_expert_report().
-*/
-#define EXPERT_REPORT_SQL        1
-#define EXPERT_REPORT_INDEXES    2
-#define EXPERT_REPORT_PLAN       3
-#define EXPERT_REPORT_CANDIDATES 4
-
-/*
-** Free an (sqlite3expert*) handle and all associated resources. There 
-** should be one call to this function for each successful call to 
-** sqlite3-expert_new().
-*/
-void sqlite3_expert_destroy(sqlite3expert*);
-
-#endif  /* !defined(SQLITEEXPERT_H) */
diff --git a/ext/expert/test_expert.c b/ext/expert/test_expert.c
deleted file mode 100644
index 064c1908a960..000000000000
--- a/ext/expert/test_expert.c
+++ /dev/null
@@ -1,220 +0,0 @@
-/*
-** 2017 April 07
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-*/
-
-#if defined(SQLITE_TEST)
-
-#include "sqlite3expert.h"
-#include <assert.h>
-#include <string.h>
-
-#if defined(INCLUDE_SQLITE_TCL_H)
-#  include "sqlite_tcl.h"
-#else
-#  include "tcl.h"
-#  ifndef SQLITE_TCLAPI
-#    define SQLITE_TCLAPI
-#  endif
-#endif
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-
-/*
-** Extract an sqlite3* db handle from the object passed as the second
-** argument. If successful, set *pDb to point to the db handle and return
-** TCL_OK. Otherwise, return TCL_ERROR.
-*/
-static int dbHandleFromObj(Tcl_Interp *interp, Tcl_Obj *pObj, sqlite3 **pDb){
-  Tcl_CmdInfo info;
-  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(pObj), &info) ){
-    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(pObj), 0);
-    return TCL_ERROR;
-  }
-
-  *pDb = *(sqlite3 **)info.objClientData;
-  return TCL_OK;
-}
-
-
-/*
-** Tclcmd:  $expert sql SQL
-**          $expert analyze
-**          $expert count
-**          $expert report STMT EREPORT
-**          $expert destroy
-*/
-static int SQLITE_TCLAPI testExpertCmd(
-  void *clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  sqlite3expert *pExpert = (sqlite3expert*)clientData;
-  struct Subcmd {
-    const char *zSub;
-    int nArg;
-    const char *zMsg;
-  } aSub[] = {
-    { "sql",       1, "TABLE",        }, /* 0 */
-    { "analyze",   0, "",             }, /* 1 */
-    { "count",     0, "",             }, /* 2 */
-    { "report",    2, "STMT EREPORT", }, /* 3 */
-    { "destroy",   0, "",             }, /* 4 */
-    { 0 }
-  };
-  int iSub;
-  int rc = TCL_OK;
-  char *zErr = 0;
-
-  if( objc<2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
-    return TCL_ERROR;
-  }
-  rc = Tcl_GetIndexFromObjStruct(interp, 
-      objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iSub
-  );
-  if( rc!=TCL_OK ) return rc;
-  if( objc!=2+aSub[iSub].nArg ){
-    Tcl_WrongNumArgs(interp, 2, objv, aSub[iSub].zMsg);
-    return TCL_ERROR;
-  }
-
-  switch( iSub ){
-    case 0: {      /* sql */
-      char *zArg = Tcl_GetString(objv[2]);
-      rc = sqlite3_expert_sql(pExpert, zArg, &zErr);
-      break;
-    }
-
-    case 1: {      /* analyze */
-      rc = sqlite3_expert_analyze(pExpert, &zErr);
-      break;
-    }
-
-    case 2: {      /* count */
-      int n = sqlite3_expert_count(pExpert);
-      Tcl_SetObjResult(interp, Tcl_NewIntObj(n));
-      break;
-    }
-
-    case 3: {      /* report */
-      const char *aEnum[] = {
-        "sql", "indexes", "plan", "candidates", 0
-      };
-      int iEnum;
-      int iStmt;
-      const char *zReport;
-
-      if( Tcl_GetIntFromObj(interp, objv[2], &iStmt) 
-       || Tcl_GetIndexFromObj(interp, objv[3], aEnum, "report", 0, &iEnum)
-      ){
-        return TCL_ERROR;
-      }
-
-      assert( EXPERT_REPORT_SQL==1 );
-      assert( EXPERT_REPORT_INDEXES==2 );
-      assert( EXPERT_REPORT_PLAN==3 );
-      assert( EXPERT_REPORT_CANDIDATES==4 );
-      zReport = sqlite3_expert_report(pExpert, iStmt, 1+iEnum);
-      Tcl_SetObjResult(interp, Tcl_NewStringObj(zReport, -1));
-      break;
-    }
-
-    default:       /* destroy */
-      assert( iSub==4 );     
-      Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
-      break;
-  }
-
-  if( rc!=TCL_OK ){
-    if( zErr ){
-      Tcl_SetObjResult(interp, Tcl_NewStringObj(zErr, -1));
-    }else{
-      extern const char *sqlite3ErrName(int);
-      Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
-    }
-  }
-  sqlite3_free(zErr);
-  return rc;
-}
-
-static void SQLITE_TCLAPI testExpertDel(void *clientData){
-  sqlite3expert *pExpert = (sqlite3expert*)clientData;
-  sqlite3_expert_destroy(pExpert);
-}
-
-/*
-** sqlite3_expert_new DB
-*/
-static int SQLITE_TCLAPI test_sqlite3_expert_new(
-  void * clientData,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  static int iCmd = 0;
-  sqlite3 *db;
-  char *zCmd = 0;
-  char *zErr = 0;
-  sqlite3expert *pExpert;
-  int rc = TCL_OK;
-
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "DB");
-    return TCL_ERROR;
-  }
-  if( dbHandleFromObj(interp, objv[1], &db) ){
-    return TCL_ERROR;
-  }
-
-  zCmd = sqlite3_mprintf("sqlite3expert%d", ++iCmd);
-  if( zCmd==0 ){
-    Tcl_AppendResult(interp, "out of memory", (char*)0);
-    return TCL_ERROR;
-  }
-
-  pExpert = sqlite3_expert_new(db, &zErr);
-  if( pExpert==0 ){
-    Tcl_AppendResult(interp, zErr, (char*)0);
-    rc = TCL_ERROR;
-  }else{
-    void *p = (void*)pExpert;
-    Tcl_CreateObjCommand(interp, zCmd, testExpertCmd, p, testExpertDel);
-    Tcl_SetObjResult(interp, Tcl_NewStringObj(zCmd, -1));
-  }
-
-  sqlite3_free(zCmd);
-  sqlite3_free(zErr);
-  return rc;
-}
-
-#endif  /* ifndef SQLITE_OMIT_VIRTUALTABLE */
-
-int TestExpert_Init(Tcl_Interp *interp){
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  struct Cmd {
-    const char *zCmd;
-    Tcl_ObjCmdProc *xProc;
-  } aCmd[] = {
-    { "sqlite3_expert_new", test_sqlite3_expert_new },
-  };
-  int i;
-
-  for(i=0; i<sizeof(aCmd)/sizeof(struct Cmd); i++){
-    struct Cmd *p = &aCmd[i];
-    Tcl_CreateObjCommand(interp, p->zCmd, p->xProc, 0, 0);
-  }
-#endif
-  return TCL_OK;
-}
-
-#endif