diff options
Diffstat (limited to 'lib/libc/db/man/recno.3')
| -rw-r--r-- | lib/libc/db/man/recno.3 | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/lib/libc/db/man/recno.3 b/lib/libc/db/man/recno.3 new file mode 100644 index 000000000000..a40e6c941a54 --- /dev/null +++ b/lib/libc/db/man/recno.3 @@ -0,0 +1,196 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)recno.3 8.3 (Berkeley) 2/21/94 +.\" +.TH RECNO 3 "February 21, 1994" +.UC 7 +.SH NAME +recno \- record number database access method +.SH SYNOPSIS +.nf +.ft B +#include <sys/types.h> +#include <db.h> +.ft R +.fi +.SH DESCRIPTION +The routine +.IR dbopen +is the library interface to database files. +One of the supported file formats is record number files. +The general description of the database access methods is in +.IR dbopen (3), +this manual page describes only the recno specific information. +.PP +The record number data structure is either variable or fixed-length +records stored in a flat-file format, accessed by the logical record +number. +The existence of record number five implies the existence of records +one through four, and the deletion of record number one causes +record number five to be renumbered to record number four, as well +as the cursor, if positioned after record number one, to shift down +one record. +.PP +The recno access method specific data structure provided to +.I dbopen +is defined in the <db.h> include file as follows: +.PP +typedef struct { +.RS +u_long flags; +.br +u_int cachesize; +.br +u_int psize; +.br +int lorder; +.br +size_t reclen; +.br +u_char bval; +.br +char *bfname; +.RE +} RECNOINFO; +.PP +The elements of this structure are defined as follows: +.TP +flags +The flag value is specified by +.IR or 'ing +any of the following values: +.RS +.TP +R_FIXEDLEN +The records are fixed-length, not byte delimited. +The structure element +.I reclen +specifies the length of the record, and the structure element +.I bval +is used as the pad character. +.TP +R_NOKEY +In the interface specified by +.IR dbopen , +the sequential record retrieval fills in both the caller's key and +data structures. +If the R_NOKEY flag is specified, the +.I cursor +routines are not required to fill in the key structure. +This permits applications to retrieve records at the end of files without +reading all of the intervening records. +.TP +R_SNAPSHOT +This flag requires that a snapshot of the file be taken when +.I dbopen +is called, instead of permitting any unmodified records to be read from +the original file. +.RE +.TP +cachesize +A suggested maximum size, in bytes, of the memory cache. +This value is +.B only +advisory, and the access method will allocate more memory rather than fail. +If +.I cachesize +is 0 (no size is specified) a default cache is used. +.TP +psize +The recno access method stores the in-memory copies of its records +in a btree. +This value is the size (in bytes) of the pages used for nodes in that tree. +If +.I psize +is 0 (no page size is specified) a page size is chosen based on the +underlying file system I/O block size. +See +.IR btree (3) +for more information. +.TP +lorder +The byte order for integers in the stored database metadata. +The number should represent the order as an integer; for example, +big endian order would be the number 4,321. +If +.I lorder +is 0 (no order is specified) the current host order is used. +.TP +reclen +The length of a fixed-length record. +.TP +bval +The delimiting byte to be used to mark the end of a record for +variable-length records, and the pad character for fixed-length +records. +If no value is specified, newlines (``\en'') are used to mark the end +of variable-length records and fixed-length records are padded with +spaces. +.TP +bfname +The recno access method stores the in-memory copies of its records +in a btree. +If bfname is non-NULL, it specifies the name of the btree file, +as if specified as the file name for a dbopen of a btree file. +.PP +The data part of the key/data pair used by the recno access method +is the same as other access methods. +The key is different. +The +.I data +field of the key should be a pointer to a memory location of type +.IR recno_t , +as defined in the <db.h> include file. +This type is normally the largest unsigned integral type available to +the implementation. +The +.I size +field of the key should be the size of that type. +.PP +In the interface specified by +.IR dbopen , +using the +.I put +interface to create a new record will cause the creation of multiple, +empty records if the record number is more than one greater than the +largest record currently in the database. +.SH "SEE ALSO" +.IR dbopen (3), +.IR hash (3), +.IR mpool (3), +.IR recno (3) +.sp +.IR "Document Processing in a Relational Database System" , +Michael Stonebraker, Heidi Stettner, Joseph Kalash, Antonin Guttman, +Nadene Lynn, Memorandum No. UCB/ERL M82/32, May 1982. +.SH BUGS +Only big and little endian byte order is supported. |