FOR UPDATE is causing a lock".
This patch tries to address problems which were exposed
during backporting of original patch to 5.1 tree.
- It ensures that we don't change locking behavior of simple
SELECT statements on InnoDB tables when they are executed
under LOCK TABLES ... READ and with @@innodb_table_locks=0.
Also we no longer pass TL_READ_DEFAULT/TL_WRITE_DEFAULT
lock types, which are supposed to be parser-only, to
handler::start_stmt() method.
- It makes check_/no_concurrent_insert.inc auxiliary scripts
more robust against changes in test cases that use them
and also ensures that they don't unnecessarily change
environment of caller.
That was a pure test issue -- filter implementation in Perl did not work
on some platform (the bug occurred on Windows Server 2008 with
Cygwin Perl 5.10.0).
for ALTER TABLE, LOAD DATA).
ROW_COUNT is now assigned according to the following rules:
- In my_ok():
- for DML statements: to the number of affected rows;
- for DDL statements: to 0.
- In my_eof(): to -1 to indicate that there was a result set.
We derive this semantics from the JDBC specification, where int
java.sql.Statement.getUpdateCount() is defined to (sic) "return the
current result as an update count; if the result is a ResultSet
object or there are no more results, -1 is returned".
- In my_error(): to -1 to be compatible with the MySQL C API and
MySQL ODBC driver.
- For SIGNAL statements: to 0 per WL#2110 specification. Zero is used
since that's the "default" value of ROW_COUNT in the diagnostics area.
Fix for bug #46947 "Embedded SELECT without FOR UPDATE is
causing a lock", with after-review fixes.
SELECT statements with subqueries referencing InnoDB tables
were acquiring shared locks on rows in these tables when they
were executed in REPEATABLE-READ mode and with statement or
mixed mode binary logging turned on.
This was a regression which were introduced when fixing
bug 39843.
The problem was that for tables belonging to subqueries
parser set TL_READ_DEFAULT as a lock type. In cases when
statement/mixed binary logging at open_tables() time this
type of lock was converted to TL_READ_NO_INSERT lock at
open_tables() time and caused InnoDB engine to acquire
shared locks on reads from these tables. Although in some
cases such behavior was correct (e.g. for subqueries in
DELETE) in case of SELECT it has caused unnecessary locking.
This patch tries to solve this problem by rethinking our
approach to how we handle locking for SELECT and subqueries.
Now we always set TL_READ_DEFAULT lock type for all cases
when we read data. When at open_tables() time this lock
is interpreted as TL_READ_NO_INSERT or TL_READ depending
on whether this statement as a whole or call to function
which uses particular table should be written to the
binary log or not (if yes then statement should be properly
serialized with concurrent statements and stronger lock
should be acquired).
Test coverage is added for both InnoDB and MyISAM.
This patch introduces an "incompatible" change in locking
scheme for subqueries used in SELECT ... FOR UPDATE and
SELECT .. IN SHARE MODE.
In 4.1 the server would use a snapshot InnoDB read for
subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE
statements, regardless of whether the binary log is on or off.
If the user required a different type of read (i.e. locking read),
he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE
clause for each individual subquery.
On of the patches for 5.0 broke this behaviour (which was not documented
or tested), and started to use locking reads fora all subqueries in SELECT ...
FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour.
transaction
BUG#52616 Temp table prevents switch binlog format from STATEMENT to ROW
Before the WL#2687 and BUG#46364, every non-transactional change that happened
after a transactional change was written to trx-cache and flushed upon
committing the transaction. WL#2687 and BUG#46364 changed this behavior and
non-transactional changes are now written to the binary log upon committing
the statement.
A binary log event is identified as transactional or non-transactional through
a flag in the Log_event which is set taking into account the underlie storage
engine on what it is stems from. In the current bug, this flag was not being
set properly when the DROP TEMPORARY TABLE was executed.
However, while fixing this bug we figured out that changes to temporary tables
should be always written to the trx-cache if there is an on-going transaction.
Otherwise, binlog events in the reversed order would be produced.
Regarding concurrency, keeping changes to temporary tables in the trx-cache is
also safe as temporary tables are only visible to the owner connection.
In this patch, we classify the following statements as unsafe:
1 - INSERT INTO t_myisam SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_myisam
3 - CREATE TEMPORARY TABLE t_myisam_temp SELECT * FROM t_myisam
On the other hand, the following statements are classified as safe:
1 - INSERT INTO t_innodb SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_innodb
The patch also guarantees that transactions that have a DROP TEMPORARY are
always written to the binary log regardless of the mode and the outcome:
commit or rollback. In particular, the DROP TEMPORARY is extended with the
IF EXISTS clause when the current statement logging format is set to row.
Finally, the patch allows to switch from STATEMENT to MIXED/ROW when there
are temporary tables but the contrary is not possible.
ChangeSet@1.2703, 2007-12-07 09:35:28-05:00, cmiller@zippy.cornsilk.net +40 -0
Bug#13174: SHA2 function
Patch contributed from Bill Karwin, paper unnumbered CLA in Seattle
Implement SHA2 functions.
Chad added code to make it work with YaSSL. Also, he removed the
(probable) bug of embedded server never using SSL-dependent
functions. (libmysqld/Makefile.am didn't read ANY autoconf defs.)
Function specification:
SHA2( string cleartext, integer hash_length )
-> string hash, or NULL
where hash_length is one of 224, 256, 384, or 512. If either is
NULL or a length is unsupported, then the result is NULL. The
resulting string is always the length of the hash_length parameter
or is NULL.
Include the canonical hash examples from the NIST in the test
results.
---
Polish and address concerns of reviewers.
Conflicts:
Text conflict in client/mysqlbinlog.cc
Text conflict in mysql-test/Makefile.am
Text conflict in mysql-test/collections/default.daily
Text conflict in mysql-test/r/mysqlbinlog_row_innodb.result
Text conflict in mysql-test/suite/rpl/r/rpl_typeconv_innodb.result
Text conflict in mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test
Text conflict in mysql-test/suite/rpl/t/rpl_row_create_table.test
Text conflict in mysql-test/suite/rpl/t/rpl_slave_skip.test
Text conflict in mysql-test/suite/rpl/t/rpl_typeconv_innodb.test
Text conflict in mysys/charset.c
Text conflict in sql/field.cc
Text conflict in sql/field.h
Text conflict in sql/item.h
Text conflict in sql/item_func.cc
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/rpl_utility.cc
Text conflict in sql/rpl_utility.h
Text conflict in sql/set_var.cc
Text conflict in sql/share/Makefile.am
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_plugin.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_table.cc
Text conflict in storage/example/ha_example.h
Text conflict in storage/federated/ha_federated.cc
Text conflict in storage/myisammrg/ha_myisammrg.cc
Text conflict in storage/myisammrg/myrg_open.c
Conflicts:
Text conflict in mysql-test/r/partition_innodb.result
Text conflict in sql/field.h
Text conflict in sql/item.h
Text conflict in sql/item_cmpfunc.h
Text conflict in sql/item_sum.h
Text conflict in sql/log_event_old.cc
Text conflict in sql/protocol.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_yacc.yy
This has been back-ported from 6.0 as the problems proved to afflict
5.1 as well.
The fix exposed two new bugs. They were reported as follows.
Bug no 52174: Sometimes wrong plan when reading a MAX value
from non-NULL index
Bug no 52173: Reading NULL value from non-NULL index gives wrong
result in embedded server
Both bugs taken together affect a much smaller class of queries than #47762,
so the fix stays for now.
Conflicts:
Text conflict in client/mysqlbinlog.cc
Text conflict in mysql-test/r/explain.result
Text conflict in mysql-test/r/subselect.result
Text conflict in mysql-test/r/subselect3.result
Text conflict in mysql-test/r/type_datetime.result
Text conflict in sql/share/Makefile.am
NULL column for NULL
The optimization to read MIN() and MAX() values from an
index did not properly handle comparisons with NULL
values. Fixed by giving up the particular optimization step
if there are non-NULL safe comparisons with NULL values, as
the result is NULL anyway.
Also, Oracle copyright notice was added to all files.
The problem is that not all column names retrieved from a SELECT
statement can be used as view column names due to length and format
restrictions. The server failed to properly check the conformity
of those automatically generated column names before storing the
final view definition on disk.
Since columns retrieved from a SELECT statement can be anything
ranging from functions to constants values of any format and length,
the solution is to rewrite to a pre-defined format any names that
are not acceptable as a view column name.
The name is rewritten to "Name_exp_%u" where %u translates to the
position of the column. To avoid this conversion scheme, define
explict names for the view columns via the column_list clause.
Also, aliases are now only generated for top level statements.
bool MDL_context::try_acquire_lock(MDL_request*)
This assert was triggered in the following way:
1) HANDLER OPEN t1 from connection 1
2) DROP TABLE t1 from connection 2. This will block due to the metadata lock
held by the open handler in connection 1.
3) DML statement (e.g. INSERT) from connection 1. This will close the table
opened by the HANDLER in 1) and release its metadata lock. This is done due
to the pending exclusive metadata lock from 2).
4) DROP TABLE t1 from connection 2 now completes and removes table t1.
5) HANDLER READ from connection 1. Since the handler table was closed in 3),
the handler code will try to reopen the table. First a new metadata lock on
t1 will be granted before the command fails since the table was removed in 4).
6) HANDLER READ from connection 1. This caused the assert.
The reason for the assert was that the MDL_request's pointer to the lock
ticket was not reset when the statement failed. HANDLER READ then tried to
acquire a lock using the same MDL_request object, triggering the assert.
This bug was only noticeable on debug builds and did not cause any problems
on release builds.
This patch fixes the problem by assuring that the pointer to the metadata
lock ticket is reset when reopening of handler tables fails.
Test case added to handler.inc
