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MDEV-17613 MIN/MAX Optimization (Select tables optimized away) does not work

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Current easy fix is not possible, because SELECT clones ha_partition
and then closes the clone which leads to unclosed transaction in
partitions we forcely prune out. We cound solve this by closing these
partitions (and release from transaction) in
change_partitions_to_open() at versioning conditions stage, but this
is problematic because table lock is acquired for each partition at
open stage and therefore must be released when we close partition
handler in change_partitions_to_open(). More details in MDEV-20376.

This should change after MDEV-20250 where mechanism of opening
partitions will be improved.

This reverts commit cdbac54df0.
This commit is contained in:
Aleksey Midenkov
2019-08-21 16:06:29 +03:00
parent 32ec5fb979
commit b96e4424fb
4 changed files with 6 additions and 66 deletions
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2
mysql-test/suite/versioning/r/partition_rotation.result
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@ -44,7 +44,7 @@ i
6
explain partitions select * from t1;
id select_type table partitions type possible_keys key key_len ref rows Extra
1 SIMPLE t1 pn_pnsp0,pn_pnsp1 ALL NULL NULL NULL NULL 2
1 SIMPLE t1 pn_pnsp0,pn_pnsp1 ALL NULL NULL NULL NULL 2 Using where
explain partitions select * from t1 for system_time as of '2001-02-04 10:20:30';
id select_type table partitions type possible_keys key key_len ref rows Extra
1 SIMPLE t1 p1_p1sp0,p1_p1sp1,p0_p0sp0,p0_p0sp1,p2_p2sp0,p2_p2sp1,pn_pnsp0,pn_pnsp1 ALL NULL NULL NULL NULL # Using where