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Removed /2 of InnoDB ref_per_key[] estimates

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The original code was there to favor index search over table scan.
This is not needed anymore as the cost calculations for table scans
and index lookups are now more exact.
This commit is contained in:
Monty
2023-01-26 11:38:31 +02:00
parent 87507bbb4f
commit 01c82173dd
13 changed files with 64 additions and 33 deletions
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mysql-test/suite/innodb/r/innodb-index-online.result
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@@ -204,7 +204,7 @@ CREATE INDEX c2d ON t1(c2);
SHOW INDEX FROM t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 c1 A 80 NULL NULL BTREE NO
t1 1 c2d 1 c2 A 10 NULL NULL YES BTREE NO
t1 1 c2d 1 c2 A 5 NULL NULL YES BTREE NO
EXPLAIN SELECT COUNT(*) FROM t1 WHERE c2 > 3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range c2d c2d 5 NULL 32 Using where; Using index