MDEV-33533: Crash at execution of DELETE when trying to use rowid filter
(Based on original patch by Oleksandr Byelkin) Multi-table DELETE can execute via "buffered" mode: at phase #1 it collects rowids of rows to be deleted, then at phase #2 in multi_delete::do_deletes() it calls handler->rnd_pos() to read rows to be deleted and deletes them. The problem occurred when phase #1 used Rowid Filter on the table that phase #2 would be deleting from. In InnoDB, h->rnd_init(scan=false) and h->rnd_pos() is an index scan over PK under the hood. So, at phase #2 ha_innobase::rnd_init() would try to use the Rowid Filter and hit an assertion inside ha_innobase::rnd_init(). Note that multi-table UPDATE works similarly but was not affected, because patch for MDEV-7487 added code to disable rowid filter for phase #2 in multi_update::do_updates(). This patch changes the approach: - It makes InnoDB not use Rowid Filter in rnd_pos() scans: it is disabled in ha_innobase::rnd_init() and enabled back in ha_innobase::rnd_end(). - multi_update::do_updates() no longer disables Rowid Filter for phase#2 as it is no longer necessary.
Showing
Please register or sign in to comment