- It turns out, there are statements that will call lex_start(thd->lex)
after parsing has been finished. lex_start() will set lex->explain=NULL,
which will lose the pointer to already allocated Explain_plan object.
- To get rid of this, switch to lazy creation of lex->explain. Now, it is
created only when we get a part ot query plan.
- Run probes like MYSQL_INSERT_SELECT_START or
MYSQL_MULTI_DELETE_START for EXPLAIN, too.
We should run them, because 1. EXPLAIN SELECT does it, and
2. MySQL also does it.
- Make EXPLAIN UPDATE/DELETE work inside SPs
- Return correct error code from mysql_delete()
- EXPLAIN <multi-DELETE> will create a multi_delete object (as it
affects the optimization). select_result will be only used for
producing EXPLAIN output.
It is now possible to kill query by query id. KILL syntax was extended to:
KILL [HARD | SOFT] [CONNECTION | QUERY [ID query_id]] [thread_id | USER user_name]
Added QUERY_ID column to INFORMATION_SCHEMA.PROCESSLIST.
Fixed tests affected by this change:
- added PROCESSLIST.QUERY_ID column
- ID is now keyword and is quoted in SHOW CREATE TABLE output
- PFS statement digest is calculated basing on token id
(not token text). Token id has shifted for keywords residing
after ID in keywords array.
- YYPARSE_PARAM and YYLEX_PARAM are removed in Bison 3.0. Deprecated
since Bison 1.875 in favor of %lex-param, %parse-param.
- %parse-param adds an argument to yyerror() as well, updated
MYSQLerror() accordingly.
- %parse-param allows to declare proper type for argument. That's
what 99% of this patch is about.
- Make query plan be re-saved after the first join execution
(saving it after JOIN::cleanup is too late because EXPLAIN output
is currently produced before that)
- Handle QPF allocation/deallocation for edge cases, like unsuccessful
BINLOG command.
- Work around the problem with UNION's direct subselects not being visible.
- Update test results ("Using temporary; Using filesort" are now always printed
last in the Extra column)
- This cset gets rid of memory leaks/crashes. Some result mismatches still remain.
- Handle statements inside SPs:
= regular statements
= SET command, which does not have its own statement.
- Handle execution of subquery from range optimizer:
allocate subquery QPFs on the same MEM_ROOT as the whole
query plan was allocated.
- Introduce back QueryPlan/QueryPlanFootprint separation for
single-table UPDATEs/DELETEs
- Create an empty QueryPlanFootprint for all kinds of queries
- Introduce "Query Plan Footprints" (abbrev. QPFs)
QPF is a part of query plan that is
1. sufficient to produce EXPLAIN output,
2. can be used to produce EXPLAIN output even after its subquery/union
was executed and deleted
3. is cheap to save so that we can always save query plans
- This patch doesn't fully address #2, we make/save strings for
a number of EXPLAIN's columns. This will be fixed.
SHOW PROCESSLIST might see a thread that started executing a query *after*
processlist has started. Don't show a negative or huge wrapped-around query execution time.
Fix problems related to reconnect. When we need to reconnect (ie. explict
stop/start of just the IO thread by user, or automatic reconnect due to
loosing network connection with the master), it is a bit complex to correctly
resume at the right point without causing duplicate or missing events in the
relay log. The previous code had multiple problems in this regard.
With this patch, the problem is solved as follows. The IO thread keeps track
(in memory) of which GTID was last queued to the relay log. If it needs to
reconnect, it resumes at that GTID position. It also counts number of events
received within the last, possibly partial, event group, and skips the same
number of events after a reconnect, so that events already enqueued before the
reconnect are not duplicated.
(There is no need to keep any persistent state; whenever we restart slave
threads after both of them being stopped (such as after server restart), we
erase the relay logs and start over from the last GTID applied by SQL thread.
But while the SQL thread is running, this patch is needed to get correct relay
log).
- Fix asserts, make sure that mysql_delete() operates on
thd->apc_target correctly* in all kinds of special cases
* - correctly means that one must switch it OFF iff it
was switched ON.
- Added a few asserts to catch similar errors.
Users can set different repplication filter rules for each replication connection, in my.cnf or command line.
But the rules set online will not record in master.info, it means if users restart MySQL, these rules will lose.
So if users wantn't their replication filter rules lose, they should write the rules in my.cnf.
Users can set rules by 2 ways:
1. Online SET command, "SET connection_name.replication_filter_settings = rules;".
2. In my.cnf, "connection_name.replication_filter_settings = rules".
If no connection_name in my.cnf, this rule will apply for ALL replication connection.
If no connetion_name in SET statement, this rull will apply for default_connection_name.
