The idea of the patch
is that every cursor gets its own lock id for table level locking.
Thus cursors are protected from updates performed within the same
connection. Additionally a list of transient (must be closed at
commit) cursors is maintained and all transient cursors are closed
when necessary. Lastly, this patch adds support for deadlock
timeouts to TLL locking when using cursors.
+ post-review fixes.
of stored routines definitions even if we already have some tables open and
locked. To avoid deadlocks in this case we have to put certain restrictions
on locking of mysql.proc table.
This allows to use stored routines safely under LOCK TABLES without explicitly
mentioning mysql.proc in the list of locked tables. It also fixes bug #11554
"Server crashes on statement indirectly using non-cached function".
We need every instruction to have its own arena, because we want to
track instruction's state (INITIALIZED_FOR_SP -> EXECUTED). Because of
`if' statements and other conditional instructions used in stored
procedures, not every instruction of a stored procedure gets executed
during the first (or even subsequent) execution of the procedure.
So it's better if we track the execution state of every instruction
independently.
All instructions of a given procedure now also share sp_head's
mem_root, but keep their own free_list.
This simplifies juggling with free Item lists in sp_head::execute.
- free_items() moved to be a member of Query_arena.
- logic of 'backup_arena' debug member of Query_arena has been
changed to support
multi-backups. Until now, TRUE 'backup_arena' meant that there is
exactly one active backup of the THD arena. Now it means simply that
the arena is used for backup, so that we can't accidentally overwrite an
existing backup. This allows doing multiple backups, e.g. in
sp_head::execute and Cursor::fetch, when THD arena is already backed up
but we want to set yet another arena (usually the 'permanent' arena,
to save permanent transformations/optimizations of a parsed tree).
ALTER, OPTIMIZE and ANALYZE statements".
In 4.1 we disabled logging of slow admin statements. The fix adds an
option to enable it back.
No test case (slow log is not tested in the test suite), but tested
manually.
+ post-review fixes (word police mainly).
We should not allow explicit or implicit transaction commits inside
of stored functions or triggers (so in autocommit mode we should not
do commits after execution of sub-statement).
Also since we don't support nested statement transactions in 5.0,
we shouldn't commit or rollback stmt transactions while we are inside
stored functions or triggers. This should be fixed in later (>=5.1)
releases.
error for LIMIT placeholder".
The patch adds grammar support for LIMIT ?, ? and changes the
type of ST_SELECT_LEX::select_limit,offset_limit from ha_rows to Item*,
so that it can point to Item_param.
