Since 0d72d085de4eb0889c926e7bc6ea584f08184b2e Tuleap uses by default PDO for all the DB queries and the chosen settings are not exactly the same than for the abstraction layer based on the mysql_* AP. Among other things, the connection is established with the charset utf8mb4 instead of utf8. When querying the permissions table CAST() is used when joining on the object_id column so that the same type is used on the two joined columns to allow MySQL to use all available indexes instead of forcing a full scan of the table. However, most of the CONVERT()/CAST() usages has been done without specifying explicitly the charset to use. In this case MySQL fallbacks on the charset used by the connection [0] so when using PDO we join on a string utf8 encoded and a value converted to a utf8mb4 encoded string. This forces MySQL to do a full scan to compute the join operation hence the degraded performance. [0] https://dev.mysql.com/doc/refman/5.6/en/cast-functions.html#function_convert Change-Id: Ia6815481433be2d352336349fbef4fe2ccb62b8b

+52 −48

Author

Thomas Gerbet (tgerbet) 2018-07-18 22:57

Committer

Thomas Gerbet (tgerbet) 2018-07-18 23:15

Hash 60437bd6363ad43c2a0fb303ae44188132814be1

Parent ccbf1920b8ce6881c0b4d0474ce8d0257117bae3

Reference git #tuleap/stable/60437bd6363ad43c2a0fb303ae44188132814be1