Constant expressions in WHERE/HAVING/ON clauses aren't cached and evaluated
for each row. This causes slowdown of query execution especially if constant
UDF/SP function are used.
Now WHERE/HAVING/ON expressions are analyzed in the top-bottom direction with
help of the compile function. When analyzer meets a constant item it
sets a flag for the tree transformer to cache the item and doesn't allow tree
walker to go deeper. Thus, the topmost item of a constant expression if
cached. This is done after all other optimizations were applied to
WHERE/HAVING/ON expressions
A helper function called cache_const_exprs is added to the JOIN class.
It calls compile method with caching analyzer and transformer on WHERE,
HAVING, ON expressions if they're present.
The cache_const_expr_analyzer and cache_const_expr_transformer functions are
added to the Item class. The first one check if the item can be cached and
the second caches it if so.
A new Item_cache_datetime class is derived from the Item_cache class.
It caches both int and string values of the underlying item independently to
avoid DATETIME aware int-to-string conversion. Thus it completely relies on
the ability of the underlying item to correctly convert DATETIME value from
int to string and vice versa.
Text conflict in mysql-test/collections/default.experimental
Text conflict in mysql-test/r/show_check.result
Text conflict in mysql-test/r/sp-code.result
Text conflict in mysql-test/suite/binlog/r/binlog_tmp_table.result
Text conflict in mysql-test/suite/rpl/t/disabled.def
Text conflict in mysql-test/t/show_check.test
Text conflict in mysys/my_delete.c
Text conflict in sql/item.h
Text conflict in sql/item_cmpfunc.h
Text conflict in sql/log.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/repl_failsafe.cc
Text conflict in sql/slave.cc
Text conflict in sql/sql_parse.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_yacc.yy
Text conflict in storage/myisam/ha_myisam.cc
Corrected results for
stm_auto_increment_bug33029.reject 2009-12-01
20:01:49.000000000 +0300
<andrei> @@ -42,9 +42,6 @@
<andrei> RETURN i;
<andrei> END//
<andrei> CALL p1();
<andrei> -Warnings:
<andrei> -Note 1592 Statement may not be safe to log in statement
format.
<andrei> -Note 1592 Statement may not be safe to log in statement
format.
There should be indeed no Note present because there is in fact autoincrement
top-level query in sp() that triggers inserting in yet another auto-inc table.
(todo: alert DaoGang to improve the test).
left join
When creating a temporary TEXT/BLOB field from an Item in
Item::make_string_field(), the field's type was unconditionally
set to the one corresponding to the maximum length (i.e.
LONGTEXT/ LONGBLOB). This resulted in problems when exactly the
same TEXT/BLOB is type required in cases like CREATE ... SELECT
or creating internal temporary tables for joins.
Fixed by calling a different constructor for Field_blob so that
an appropriate type is used depending on the Item's max_length
value.
------------------------------------------------------------
revno: 2572.23.1
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-03-19 09:03:08 -0300
message:
Bug#17954 Threads_connected > Threads_created
The problem is that insert delayed threads are counted as connected
but not as created, leading to a Threads_connected value greater then
the Threads_created value.
The solution is to enforce the documented behavior that the
Threads_connected value shall be the number of currently
open connections and that Threads_created shall be the
number of threads created to handle connections.
------------------------------------------------------------
revno: 2476.1116.1
committer: davi@mysql.com/endora.local
timestamp: Fri 2007-12-14 10:10:19 -0200
message:
DROP TABLE under LOCK TABLES simultaneous to a FLUSH TABLES
WITH READ LOCK (global read lock) can lead to a deadlock.
The solution is to not wait for the global read lock if the
thread is holding any locked tables.
Related to bugs 23713 and 32395. This issues is being fixed
only on 6.0 because it depends on the fix for bug 25858 --
which was fixed only on 6.0.
------------------------------------------------------------
revno: 2476.784.3
committer: davi@moksha.local
timestamp: Tue 2007-10-02 21:27:31 -0300
message:
Bug#25858 Some DROP TABLE under LOCK TABLES can cause deadlocks
When a client (connection) holds a lock on a table and attempts to
drop (obtain a exclusive lock) on a second table that is already
held by a second client and the second client then attempts to
drop the table that is held by the first client, leads to a
circular wait deadlock. This scenario is very similar to trying to
drop (or rename) a table while holding read locks and are
correctly forbidden.
The solution is to allow a drop table operation to continue only
if the table being dropped is write (exclusively) locked, or if
the table is temporary, or if the client is not holding any
locks. Using this scheme prevents the creation of a circular
chain in which each client is waiting for one table that the
next client in the chain is holding.
This is incompatible change, as can be seen by number of tests
cases that needed to be fixed, but is consistent with respect to
behavior of the different scenarios in which the circular wait
might happen.
The additional patch. That 'loadxml.test' failure was actually about our testing system,
not the code.
Firstly we need a new mysqltest command, wich i called 'send_eval'. So the expression
can be evaluated, then started in a parallel thread. We only have separane 'send' and
'eval' commands at the moment.
Then we need to add the waiting code after the 'KILL' to our test, so the thread will be killed
before the test goes further. The present 'reap' command doesn't handle the killed threads
well.
per-file comments:
client/mysqltest.cc
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
The 'send_eval' command implemented.
mysql-test/r/loadxml.result
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
test result updated.
mysql-test/t/loadxml.test
Bug#42520 killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
test case added.
------------------------------------------------------------
revno: 2476.784.4
revision-id: sp1r-davi@moksha.local-20071008114751-46069
parent: sp1r-davi@moksha.local-20071003002731-48537
committer: davi@moksha.local
timestamp: Mon 2007-10-08 08:47:51 -0300
message:
Bug#27249 table_wild with alias: select t1.* as something
Aliases to table wildcards are silently ignored, but they should
not be allowed as it is non-standard and currently useless. There
is not point in having a alias to a wildcard of column names.
The solution is to rewrite the select_item rule so that aliases
for table wildcards are not accepted.
Contribution by Martin Friebe
------------------------------------------------------------
revno: 2597.4.17
revision-id: sp1r-davi@mysql.com/endora.local-20080328174753-24337
parent: sp1r-anozdrin/alik@quad.opbmk-20080328140038-16479
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-03-28 14:47:53 -0300
message:
Bug#15192 "fatal errors" are caught by handlers in stored procedures
The problem is that fatal errors (e.g.: out of memory) were being
caught by stored procedure exception handlers which could cause
the execution to not be stopped due to a continue handler.
The solution is to not call any exception handler if the error is
fatal and send the fatal error to the client.
------------------------------------------------------------
revno: 2597.37.3
revision-id: sp1r-davi@mysql.com/endora.local-20080328123626-16430
parent: sp1r-anozdrin/alik@quad.opbmk-20080327125300-11290
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-03-28 09:36:26 -0300
message:
Bug#10374 GET_LOCK does not let connection to close on the server side if it's aborted
The problem is that the server doesn't detect aborted connections which
are waiting on a lock or sleeping (user sleep), wasting system resources
for a connection that is already dead.
The solution is to peek at the connection every five seconds to verify if
the connection is not aborted. A aborted connection is detect by polling
the connection socket for available data to be read or end of file and in
case of eof, the wait is aborted and the connection killed.
------------------------------------------------------------
revno: 2572.2.1
revision-id: sp1r-davi@mysql.com/endora.local-20080227225948-16317
parent: sp1r-anozdrin/alik@quad.-20080226165712-10409
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-02-27 19:59:48 -0300
message:
Bug#27525 table not found when using multi-table-deletes with aliases over several databas
Bug#30234 Unexpected behavior using DELETE with AS and USING
The multi-delete statement has a documented limitation that
cross-database multiple-table deletes using aliases are not
supported because it fails to find the tables by alias if it
belongs to a different database. The problem is that when
building the list of tables to delete from, if a database
name is not specified (maybe an alias) it defaults to the
name of the current selected database, making impossible to
to properly resolve tables by alias later. Another problem
is a inconsistency of the multiple table delete syntax that
permits ambiguities in a delete statement (aliases that refer
to multiple different tables or vice-versa).
The first step for a solution and proper implementation of
the cross-databse multiple table delete is to get rid of any
ambiguities in a multiple table statement. Currently, the parser
is accepting multiple table delete statements that have no obvious
meaning, such as:
DELETE a1 FROM db1.t1 AS a1, db2.t2 AS a1;
DELETE a1 AS a1 FROM db1.t1 AS a1, db2.t2 AS a1;
The solution is to resolve the left part of a delete statement
using the right part, if the a table on right has an alias,
it must be referenced in the left using the given alias. Also,
each table on the left side must match unambiguously only one
table in the right side.
------------------------------------------------------------
revno: 2630.39.3
revision-id: davi.arnaut@sun.com-20081210215359-i876m4zgc2d6rzs3
parent: kostja@sun.com-20081208222938-9es7wl61moli71ht
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 36649-6.0
timestamp: Wed 2008-12-10 19:53:59 -0200
message:
Bug#36649: Condition area is not properly cleaned up after stored routine invocation
The problem is that the diagnostics area of a trigger is not
isolated from the area of the statement that caused the trigger
invocation. In MySQL terms, it means that warnings generated
during the execution of the trigger are not removed from the
"warning area" at the end of the execution.
Before this fix, the rules for MySQL message list life cycle (see
manual entry for SHOW WARNINGS) did not apply to statements
inside stored programs:
- The manual says that the list of messages is cleared by a
statement that uses a table (any table). However, such
statement, if run inside a stored program did not clear the
message list.
- The manual says that the list is cleared by a statement that
generates a new error or a warning, but this was not the case
with stored program statements either and is changed to be the
case as well.
In other words, after this fix, a statement has the same effect
on the message list regardless of whether it's executed inside a
stored program/sub-statement or not.
This introduces an incompatible change:
- before this fix, a, e.g. statement inside a trigger could
never clear the global warning list
- after this fix, a trigger that generates a warning or uses a
table, clears the global warning list
- however, when we leave a trigger or a function, the caller's
warning information is restored (see more on this below).
This change is not backward compatible as it is intended to make
MySQL behavior similar to the SQL standard behavior:
A stored function or trigger will get its own "warning area" (or,
in standard terminology, diagnostics area). At the beginning of
the stored function or trigger, all messages from the caller area
will be copied to the area of the trigger. During execution, the
message list will be cleared according to the MySQL rules
described on the manual (SHOW WARNINGS entry). At the end of the
function/trigger, the "warning area" will be destroyed along with
all warnings it contains, except that if the last statement of
the function/trigger generated messages, these are copied into
the "warning area" of the caller.
Consequently, statements that use a table or generate a warning
*will* clear warnings inside the trigger, but that will have no
effect to the warning list of the calling (outer) statement.
mysql-next-mr-bugfixing.
Bug no 32858 was fixed in two different ways in what was
then called mysql 5.1 and 6.0. The fix in 6.0 was very
different since bugfix no 33204 was present. Furthermore,
the two fixes were not compatible. Hence in order to
backport Bug#33204 to the 5.1-based mysql-next-mr-bugfixing,
it was necessary to remove the 5.1 fix of 32858 and apply
the 6.0 version of the fix.
