Fixed MDEV-331: last_insert_id() returns a signed number
mysql-test/r/auto_increment.result:
Added test case
mysql-test/t/auto_increment.test:
Added test case
sql/item_func.h:
Changed last_insert_id() to be unsigned.
The --debug-no-sync incorrectly defaulted to ON, disabling sync calls
by default which can loose data or cause corruption. Also, the code
used fsync() instead of the sometimes more efficient fdatasync().
- Make SHOW EXPLAIN code take into account that st_select_lex object without joins can be
a full-featured SELECTs which were already executed and cleaned up.
Analysis:
When the method JOIN::choose_subquery_plan() decided to apply
the IN-TO-EXISTS strategy, it set the unit and select_lex
uncacheable flag to UNCACHEABLE_DEPENDENT_INJECTED unconditionally.
As result, even if IN-TO-EXISTS injected non-correlated predicates,
the subquery was still treated as correlated.
Solution:
Set the subquery as correlated only if the injected predicate(s) depend
on the outer query.
- The problem was that create_ref_for_key() would act differently, depending on
whether we're running EXPLAIN or the actual query.
- As the first step, fixed the EXPLAIN printout not to depend on actions in create_ref_for_key().
backport dmitry.shulga@oracle.com-20120209125742-w7hdxv0103ymb8ko from mysql-trunk:
Patch for bug#11764747 (formerly known as 57612): SET GLOBAL READ_ONLY=1 cannot
progress when a table is locked with LOCK TABLES.
The reason for the bug was that mysql server makes a flush of all open tables
during handling of statement 'SET GLOBAL READ_ONLY=1'. Therefore if some of
these tables were locked by "LOCK TABLE ... READ" from a different connection,
then execution of statement 'SET GLOBAL READ_ONLY=1' would be waiting for
the lock for such table even if the table was locked in a compatible read mode.
Flushing of all open tables before setting of read_only system variable
is inherited from 5.1 implementation since this was the only possible approach
to ensure that there isn't any pending write operations on open tables.
Start from version 5.5 and above such behaviour is guaranteed by the fact
that we acquire global_read_lock before setting read_only flag. Since
acquiring of global_read_lock is successful only when there isn't any
active write operation then we can remove flushing of open tables from
processing of SET GLOBAL READ_ONLY=1.
This modification changes the server behavior so that read locks held
by other connections (LOCK TABLE ... READ) no longer will block attempts
to enable read_only.
Analysis:
The crash is a result of Item_cache_temporal::example not being set
(it is NULL). It turns out that the value of Item_cache_temporal
may be set directly by calling Item_cache_temporal::store_packed
without ever setting the "example" of this Item_cache. Therefore
the failing assertion is too narrow.
Solution:
Remove the assert.
In principle we could overwrite this method for Item_cache_temporal,
but it doesn't make sense just for this assert.
The constructor for Query_log_event allocated 2 bytes too few for
extra space needed by Query cache. (Not sure if this is reproducible
in practice, as there are often a couple of extra bytes allocated
for unused string zero terminators, but better safe than sorry).
Analysis:
When a subquery that needs a temp table is executed during
the prepare or optimize phase of the outer query, at the end
of the subquery execution all the JOIN_TABs of the subquery
are replaced by a new JOIN_TAB that selects from the temp table.
However that temp table has no corresponding TABLE_LIST.
Once EXPLAIN execution reaches its last phase, it tries to print
the names of the subquery tables through its TABLE_LISTs, but in
the case of this bug there is no such TABLE_LIST (it is NULL),
hence a crash.
Solution:
The fix is to block subquery evaluation inside
Item_func_like::fix_fields and Item_func_like::select_optimize()
using the Item::is_expensive() test.
- In JOIN::exec(), make the having->update_used_tables() call before we've
made the JOIN::cleanup(full=true) call. The latter frees SJ-Materialization
structures, which correlated subquery predicate items attempt to walk afterwards.
- Don't try to produce plans after JOIN::cleanup() has been called, because:
= JOIN::cleanup leaves data structures in partially-cleaned state
= Walking them is hazardous (see this bug), and has funny effects
(See previous commits, "Using join cache" may or may not be shown)
= Changing data structures to be persisted may cause unwanted side effects
- The consequence is that SHOW EXPLAIN will show "Query plan already deleted" when e.g.
reading data after filesort.
Analysis:
The optimizer detects an empty result through constant table optimization.
Then it calls return_zero_rows(), which in turns calls inderctly
Item_maxmin_subselect::no_rows_in_result(). The latter method set "value=0",
however "value" is pointer to Item_cache, and not just an integer value.
All of the Item_[maxmin | singlerow]_subselect::val_XXX methods does:
if (forced_const)
return value->val_real();
which of course crashes when value is a NULL pointer.
Solution:
When the optimizer discovers an empty result set, set
Item_singlerow_subselect::value to a FALSE constant Item instead of NULL.
Handle the 'set read_only=1' in lighter way, than the FLUSH TABLES READ LOCK;
For the transactional engines we don't wait for operations on that tables to finish.
per-file comments:
mysql-test/r/read_only_innodb.result
MDEV-136 Non-blocking "set read_only".
test result updated.
mysql-test/t/read_only_innodb.test
MDEV-136 Non-blocking "set read_only".
test case added.
sql/mysql_priv.h
MDEV-136 Non-blocking "set read_only".
The close_cached_tables_set_readonly() declared.
sql/set_var.cc
MDEV-136 Non-blocking "set read_only".
Call close_cached_tables_set_readonly() for the read_only::set_var.
sql/sql_base.cc
MDEV-136 Non-blocking "set read_only".
Parameters added to the close_cached_tables implementation,
close_cached_tables_set_readonly declared.
Prevent blocking on the transactional tables if the
set_readonly_mode is on.
- make make_cond_after_sjm() correctly handle OR clauses where one branch refers to the semi-join table
while the other branch refers to the non-semijoin table.
- It turns out, there is a case where the join is degenerate, but
join->table_count!= && join->tables_list!=NULL. Need to also check
if join->zero_result_cause!=NULL, too.
- There is a slight problem: The code sets
zero_result_cause= "no matching row in const table"
when NOT running EXPLAIN. The result is that SHOW EXPLAIN will show this line while
regular EXPLAIN will not.
If we did nothing in resolving unique table conflict we should not retry (it leed to infinite loop).
Now we retry (recheck) unique table check only in case if we materialized a table.
- Let fix_semijoin_strategies_for_picked_join_order() set
POSITION::prefix_record_count for POSITION records that it copies from
SJ_MATERIALIZATION_INFO::tables.
(These records do not have prefix_record_count set, because they are optimized
as joins-inside-semijoin-nests, without full advance_sj_state() processing).
