mariadb/storage/innobase/include/row0ext.h
Jimmy Yang 9e2b7fa7d5 Implement worklog #5743 InnoDB: Lift the limit of index key prefixes.
With this change, the index prefix column length lifted from 767 bytes
to 3072 bytes if "innodb_large_prefix" is set to "true".

rb://603 approved by Marko
2011-05-31 02:12:32 -07:00

102 lines
3.7 KiB
C

/*****************************************************************************
Copyright (c) 2006, 2009, Innobase Oy. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************/
/**************************************************//**
@file include/row0ext.h
Caching of externally stored column prefixes
Created September 2006 Marko Makela
*******************************************************/
#ifndef row0ext_h
#define row0ext_h
#include "univ.i"
#include "row0types.h"
#include "data0types.h"
#include "mem0mem.h"
#include "dict0types.h"
/********************************************************************//**
Creates a cache of column prefixes of externally stored columns.
@return own: column prefix cache */
UNIV_INTERN
row_ext_t*
row_ext_create(
/*===========*/
ulint n_ext, /*!< in: number of externally stored columns */
const ulint* ext, /*!< in: col_no's of externally stored columns
in the InnoDB table object, as reported by
dict_col_get_no(); NOT relative to the records
in the clustered index */
ulint flags, /*!< in: table->flags */
const dtuple_t* tuple, /*!< in: data tuple containing the field
references of the externally stored
columns; must be indexed by col_no;
the clustered index record must be
covered by a lock or a page latch
to prevent deletion (rollback or purge). */
mem_heap_t* heap); /*!< in: heap where created */
/********************************************************************//**
Looks up a column prefix of an externally stored column.
@return column prefix, or NULL if the column is not stored externally,
or pointer to field_ref_zero if the BLOB pointer is unset */
UNIV_INLINE
const byte*
row_ext_lookup_ith(
/*===============*/
const row_ext_t* ext, /*!< in/out: column prefix cache */
ulint i, /*!< in: index of ext->ext[] */
ulint* len); /*!< out: length of prefix, in bytes,
at most the length determined by
DICT_MAX_FIELD_LEN_BY_FORMAT() */
/********************************************************************//**
Looks up a column prefix of an externally stored column.
@return column prefix, or NULL if the column is not stored externally,
or pointer to field_ref_zero if the BLOB pointer is unset */
UNIV_INLINE
const byte*
row_ext_lookup(
/*===========*/
const row_ext_t* ext, /*!< in: column prefix cache */
ulint col, /*!< in: column number in the InnoDB
table object, as reported by
dict_col_get_no(); NOT relative to the
records in the clustered index */
ulint* len); /*!< out: length of prefix, in bytes,
at most the length determined by
DICT_MAX_FIELD_LEN_BY_FORMAT() */
/** Prefixes of externally stored columns */
struct row_ext_struct{
ulint n_ext; /*!< number of externally stored columns */
const ulint* ext; /*!< col_no's of externally stored columns */
byte* buf; /*!< backing store of the column prefix cache */
ulint max_len;/*!< maximum prefix length, it could be
REC_ANTELOPE_MAX_INDEX_COL_LEN or
REC_VERSION_56_MAX_INDEX_COL_LEN depending
on row format */
ulint len[1]; /*!< prefix lengths; 0 if not cached */
};
#ifndef UNIV_NONINL
#include "row0ext.ic"
#endif
#endif