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.
Let us invoke wait_all_purged.inc right before the workload.
Starting with MDEV-12288 in MariaDB Server 10.3, also INSERT
generates purge workload. If we do not ensure that purge has
run to completion, the results on 10.3 and later could be
nondeterministic.
If there're multiple row versions in InnoDB, reading one row from PK
may have O(N) complexity and reading from secondary keys may have
O(N^2) complexity.
The problem occurs when there are many pending versions of the same
row, meaning that the primary key is the same, but a secondary key is
different. The slowdown occurs when the secondary index is
traversed. This patch creates a helper class for the function
row_sel_get_clust_rec_for_mysql() which can remember and re-use
cached_clust_rec & cached_old_vers so that rec_get_offsets() does not
need to be called over and over for the clustered record.
Corrections by Kevin Lewis <kevin.lewis@oracle.com>
MDEV-20341 Unstable innodb.innodb_bug14704286
Removed test that tested the ability of interrupting long query which
is not long anymore.
