diff options
Diffstat (limited to 'mysql-test/r/group_by.result')
| -rw-r--r-- | mysql-test/r/group_by.result | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/mysql-test/r/group_by.result b/mysql-test/r/group_by.result index 07773960e5a..f27ae67adff 100644 --- a/mysql-test/r/group_by.result +++ b/mysql-test/r/group_by.result @@ -1346,12 +1346,43 @@ id select_type table type possible_keys key key_len ref rows Extra EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR JOIN (PRIMARY,i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 +# +# For this explain, the query plan is weird: if we are using +# the primary key for reasons other than doing grouping, can't +# GROUP BY code take advantage of this? Well, currently it doesnt: EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (PRIMARY,i2) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra -1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index +1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index; Using filesort +# Here's a proof it is really doing sorting: +flush status; +SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (PRIMARY,i2) GROUP BY a; +show status like 'Sort_%'; +Variable_name Value +Sort_merge_passes 0 +Sort_priority_queue_sorts 0 +Sort_range 0 +Sort_rows 144 +Sort_scan 1 +# Proof ends. +# +# For this explain, the query plan is weird: if we are using +# the primary key for reasons other than doing sorting, can't +# ORDER BY code take advantage of this? Well, currently it doesnt: EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY,i2) ORDER BY a; id select_type table type possible_keys key key_len ref rows Extra -1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index +1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index; Using filesort +# Here's a proof it is really doing sorting: +flush status; +SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY,i2) ORDER BY a; +show status like 'Sort_%'; +Variable_name Value +Sort_merge_passes 0 +Sort_priority_queue_sorts 0 +Sort_range 0 +Sort_rows 144 +Sort_scan 1 +# Proof ends. +# SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY,i2) ORDER BY a; a 1 @@ -2678,3 +2709,17 @@ NULL 100098 100099 drop table t0,t1,t2; +# +# MDEV-9602 crash in st_key::actual_rec_per_key when group by constant +# +create table t1 (a date not null,unique (a)) engine=innodb; +Warnings: +Warning 1286 Unknown storage engine 'innodb' +Warning 1266 Using storage engine MyISAM for table 't1' +select distinct a from t1 group by 'a'; +a +insert into t1 values("2001-02-02"),("2001-02-03"); +select distinct a from t1 group by 'a'; +a +2001-02-02 +drop table t1; |