- Added the parameter stats_persistent=0 for InnoDB engine.
- Before printing metadata_lock_info query, make sure that
InnoDB does complete purging.
Reviewed by: Marko Mäkelä
Fix the side effect of MDEV-4750 (reenabling innodb_stats_persistent),
so that sporadic MDL acquisition for this table does not interfere with
SELECT from information_schema.metadata_lock_info
Part of MDEV-5336 Implement LOCK FOR BACKUP
- Added new locks to MDL_BACKUP for all stages of backup locks and
a new MDL lock needed for backup stages.
- Renamed MDL_BACKUP_STMT to MDL_BACKUP_DDL
- flush_tables() takes a new parameter that decides what should be flushed.
- InnoDB, Aria (transactional tables with checksums), Blackhole, Federated
and Federatedx tables are marked to be safe for online backup. We are
using MDL_BACKUP_TRANS_DML instead of MDL_BACKUP_DML locks for these
which allows any DML's to proceed for these tables during the whole
backup process until BACKUP STAGE COMMIT which will block the final
commit.
