This patch allowed transformation of EXISTS subqueries into equivalent
IN predicands at the top level of WHERE conditions for multi-table UPDATE
and DELETE statements. There was no reason to prohibit the transformation
for such statements. The transformation provides more opportunities of
using semi-join optimizations.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
This essentially reverts commit 4e89ec6692
and only disables InnoDB persistent statistics for tests where it is
desirable. By design, InnoDB persistent statistics will not be updated
except by ANALYZE TABLE or by STATS_AUTO_RECALC.
The internal transactions that update persistent InnoDB statistics
in background tasks (with innodb_stats_auto_recalc=ON) may cause
nondeterministic query plans or interfere with some tests that deal
with other InnoDB internals, such as the purge of transaction history.
