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mysql-5.5 merge

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This commit is contained in:
Sergei Golubchik
2012-01-16 20:16:35 +01:00
parent c56483d972 ed1ba992c1
commit 38e3ae155d
321 changed files with 5432 additions and 3995 deletions
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12
sql/opt_range.cc
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@ -11592,6 +11592,11 @@ cost_group_min_max(TABLE* table, KEY *index_info, uint used_key_parts,
except MIN and MAX. For queries with DISTINCT, aggregate functions
are allowed.
SA5. The select list in DISTINCT queries should not contain expressions.
SA6. Clustered index can not be used by GROUP_MIN_MAX quick select
for AGG_FUNC(DISTINCT ...) optimization because cursor position is
never stored after a unique key lookup in the clustered index and
furhter index_next/prev calls can not be used. So loose index scan
optimization can not be used in this case.
GA1. If Q has a GROUP BY clause, then GA is a prefix of I. That is, if
G_i = A_j => i = j.
GA2. If Q has a DISTINCT clause, then there is a permutation of SA that
@ -12086,6 +12091,13 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time)
Field::itMBR : Field::itRAW))
DBUG_RETURN(NULL);
/*
Check (SA6) if clustered key is used
*/
if (is_agg_distinct && index == table->s->primary_key &&
table->file->primary_key_is_clustered())
DBUG_RETURN(NULL);
/* The query passes all tests, so construct a new TRP object. */
read_plan= new (param->mem_root)
TRP_GROUP_MIN_MAX(have_min, have_max, is_agg_distinct,