Hi, Sergey! On Aug 04, Sergey Vojtovich wrote:

revision-id: 634e130b00bc900d1b7b8a8df6c13b1701f84b30 (mariadb-5.5.50-24-g634e130) parent(s): 2f55f0b010619a09870ba704b55dd1426a158f1d committer: Sergey Vojtovich timestamp: 2016-08-04 15:51:17 +0400 message:

MDEV-10424 - Assertion `ticket == __null' failed in MDL_request::set_type

Reexecution of prepared "ANALYZE TABLE merge_table, table" may miss to reinitialize "table" for subsequent execution and trigger assertion failure.

This happens because MERGE engine may adjust table->next_global chain, which gets cleared by close_thread_tables()/ha_myisammrg::detach_children() later. Since reinitilization iterates next_global chain, it won't see tables following merge table.

Fixed by appending saved next_global chain after merge children.

looks ok to me, but let elena do some extra testing of this, please Regards, Sergei Chief Architect MariaDB and security@mariadb.org