BUG#47073 - valgrind errs, corruption,failed repair of partition,
low myisam_sort_buffer_size
Fixed race conditions discovered with the provided test case and
stabilized test case.
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
low myisam_sort_buffer_size
Repair by sort (default) or parallel repair of a MyISAM table
(doesn't matter partitioned or not) as well as bulk inserts
and enable indexes some times didn't failover to repair with
key cache.
The problem was that after unsuccessful attempt, data file was
closed. Whereas repair with key cache requires open data file.
Fixed by reopening data file.
Also fixed a valgrind warning, which may appear during repair
by sort or parallel repair with certain myisam_sort_buffer_size
number of rows and length of an index entry (very dependent).
Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.
The Debug Sync Facility allows to place synchronization points
in the code:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Send a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- send a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
Please find more information in the top comment in debug_sync.cc
or in the worklog entry.
INSERT ... SELECT ...
Problem was that when bulk insert is used on an empty
table/partition, it disables the indexes for better
performance, but in this specific case it also tries
to read from that partition using an index, which is
not possible since it has been disabled.
Solution was to allow index reads on disabled indexes
if there are no records.
Also reverted the patch for bug#38005, since that was a workaround
in the partitioning engine instead of a fix in myisam.
bzr branch mysql-5.1-performance-version mysql-trunk # Summit
cd mysql-trunk
bzr merge mysql-5.1-innodb_plugin # which is 5.1 + Innodb plugin
bzr rm innobase # remove the builtin
Next step: build, test fixes.
the auto_increment value
This is an alternative patch that instead of allowing RECREATE TABLE
on TRUNCATE TABLE it implements reset_auto_increment that is called
after delete_all_rows.
Note: this bug was fixed by Mattias Jonsson:
Pusing this patch: http://lists.mysql.com/commits/70370
This patch fixes compilation warning, "conversion from 'time_t' to 'ulong',
possible loss of data".
The fix is to typecast time_t to ulong before assigning it to ulong.
Backported this from 6.0-bugteam tree.
This patch adds corrections to the original patch
submitted 2009-04-08 (http://lists.mysql.com/commits/71607):
- fixed that the original patch didn't work because of an
incorrect condition;
- added a test case.
Killing the insert-select statement corrupts the MyISAM table only
when the destination table is empty and when it has indexes. When
we bulk insert huge data and if the destination table is empty we
disable the indexes for fast inserts, data is then inserted and
indexes are re-enabled after bulk_insert operation
Killing the query, aborts the repair table operation during enable
indexes phase leading to table corruption.
We now truncate the table when we detect that enable indexes is
killed for bulk insert query.As we have an empty table before the
operation, we can fix by truncating the table.
A bug in the initialization of key segment information made it point
to the wrong bit, since a bit index was used when its int value
was needed. This lead to misinterpretation of bit columns
read from MyISAM record format when a NULL bit pushed them over
a byte boundary.
Fixed by using the int value of the bit instead.
single quote fails in 5.1.x
Performing fulltext prefix search (a word with truncation
operator) may cause a dead-loop.
The problem was in smarter index merge algorithm - it was writing
record reference to an incorrect memory area.
Killing insert-select statement on MyISAM corrupts the table.
Killing the insert-select statement corrupts the MyISAM table only
when the destination table is empty and when it has indexes. When
we bulk insert huge data and if the destination table is empty we
disable the indexes for fast inserts, data is then inserted and
indexes are re-enabled after bulk_insert operation
Killing the query, aborts the repair table operation during enable
indexes phase leading to table corruption.
We now truncate the table when we detect that enable indexes is
killed for bulk insert query.As we have an empty table before the
operation, we can fix by truncating the table.
Currently the memory map is being created
with a size that is greater than the size
of the underlying datafile. This can cause
varying behaviour,
e.g.
In windows the size of the datafile
is increased, while on linux it remains
the same.
This fix removes the increment margin to
the size that is used while creating the
memory map.
The conformance checker was not taking into
account, and, making concessions for acceptable
incompatibilites in tables created by
versions earlier than 4.1.
The current patch relaxes the conformance
checker to ignore differences in key_alg
and language for tables created by versions
earlier than 4.1.
Probe definition file is now a separate file that is copied during
build to the correct location, this enforces dependency requirements
correctly and allows builds to work when using the current or separate
build directories
