mariadb/include/row0purge.h
marko a65020d27f branches/zip: When logging updates or deletes in the undo log, store long
enough prefixes of externally stored columns, so that purge will not have
to dereference any BLOB pointers, which may be invalid.  This will not be
necessary for logging inserts, because inserts are no-ops in purge, and
the record will remain locked during transaction rollback.

TODO: in dict_build_table_def_step() or dict_build_index_def_step(),
prevent the creation of tables with too many columns for which a
prefix index is defined.  This is because there is a size limit of undo
log records, and for each prefix-indexed column, the log must store
REC_MAX_INDEX_COL_LEN + BTR_EXTERN_FIELD_REF_SIZE bytes.

trx_undo_page_report_insert(): Assert that the index is clustered.

trx_undo_page_fetch_ext(): New function, for fetching the BLOB prefix
in trx_undo_page_report_modify().

trx_undo_page_report_modify(): Write long enough prefixes of the externally
stored columns to the undo log.

trx_undo_rec_get_partial_row(): Remove the parameter "ext".  Assert that
the undo log contains long enough prefixes of the externally stored columns.

purge_node_t: Remove the field "ext".
2007-12-05 14:10:15 +00:00

79 lines
2.4 KiB
C

/******************************************************
Purge obsolete records
(c) 1997 Innobase Oy
Created 3/14/1997 Heikki Tuuri
*******************************************************/
#ifndef row0purge_h
#define row0purge_h
#include "univ.i"
#include "data0data.h"
#include "btr0types.h"
#include "btr0pcur.h"
#include "dict0types.h"
#include "trx0types.h"
#include "que0types.h"
#include "row0types.h"
/************************************************************************
Creates a purge node to a query graph. */
purge_node_t*
row_purge_node_create(
/*==================*/
/* out, own: purge node */
que_thr_t* parent, /* in: parent node, i.e., a thr node */
mem_heap_t* heap); /* in: memory heap where created */
/***************************************************************
Does the purge operation for a single undo log record. This is a high-level
function used in an SQL execution graph. */
que_thr_t*
row_purge_step(
/*===========*/
/* out: query thread to run next or NULL */
que_thr_t* thr); /* in: query thread */
/* Purge node structure */
struct purge_node_struct{
que_common_t common; /* node type: QUE_NODE_PURGE */
/*----------------------*/
/* Local storage for this graph node */
dulint roll_ptr;/* roll pointer to undo log record */
trx_undo_rec_t* undo_rec;/* undo log record */
trx_undo_inf_t* reservation;/* reservation for the undo log record in
the purge array */
dulint undo_no;/* undo number of the record */
ulint rec_type;/* undo log record type: TRX_UNDO_INSERT_REC,
... */
btr_pcur_t pcur; /* persistent cursor used in searching the
clustered index record */
ibool found_clust;/* TRUE if the clustered index record
determined by ref was found in the clustered
index, and we were able to position pcur on
it */
dict_table_t* table; /* table where purge is done */
ulint cmpl_info;/* compiler analysis info of an update */
upd_t* update; /* update vector for a clustered index
record */
dtuple_t* ref; /* NULL, or row reference to the next row to
handle */
dtuple_t* row; /* NULL, or a copy (also fields copied to
heap) of the indexed fields of the row to
handle */
dict_index_t* index; /* NULL, or the next index whose record should
be handled */
mem_heap_t* heap; /* memory heap used as auxiliary storage for
row; this must be emptied after a successful
purge of a row */
};
#ifndef UNIV_NONINL
#include "row0purge.ic"
#endif
#endif