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row0sel.c:

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Fix bug: if a primary key contains more than one column, then MySQL seems to do fetch next even for a unique search condition: this in turn caused unnecessary locking which did not agree what the InnoDB manual promised
This commit is contained in:
heikki@hundin.mysql.fi 2003-09-12 00:31:43 +03:00
parent 541189e746
commit be05042bae
1 changed files with 12 additions and 16 deletions
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26
innobase/row/row0sel.c
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@ -2810,21 +2810,6 @@ row_search_for_mysql(
mode = pcur->search_mode;
}
if ((direction == ROW_SEL_NEXT || direction == ROW_SEL_PREV)
&& pcur->old_stored != BTR_PCUR_OLD_STORED) {
/* MySQL sometimes seems to do fetch next or fetch prev even
if the search condition is unique; this can, for example,
happen with the HANDLER commands; we do not always store the
pcur position in this case, so we cannot restore cursor
position, and must return immediately */
/* printf("%s record not found 1\n", index->name); */
trx->op_info = (char *) "";
return(DB_RECORD_NOT_FOUND);
}
mtr_start(&mtr);
/* In a search where at most one record in the index may match, we
@ -2841,6 +2826,16 @@ row_search_for_mysql(
&& dtuple_get_n_fields(search_tuple)
== dict_index_get_n_unique(index)) {
unique_search = TRUE;
/* Even if the condition is unique, MySQL seems to try to
retrieve also a second row if a primary key contains more than
1 column. Return immediately if this is not a HANDLER
command. */
if (direction != 0 && !prebuilt->used_in_HANDLER) {
return(DB_RECORD_NOT_FOUND);
}
}
/*-------------------------------------------------------------*/
@ -2854,6 +2849,7 @@ row_search_for_mysql(
if (unique_search
&& index->type & DICT_CLUSTERED
&& direction == 0
&& !prebuilt->templ_contains_blob
&& !prebuilt->used_in_HANDLER
&& (prebuilt->mysql_row_len < UNIV_PAGE_SIZE / 8)) {