PARTITION STATISTICS
Problem was the fix for bug#11756867; It always used the first
partitions, and stopped after it checked 10 [sub]partitions.
(or until it found a partition which would contain a match).
This results in bad statistics for tables where the first 10 partitions
don't represent the majority of the data (like when the first 10
partitions only contained a few rows in total).
The solution was to take statisics from the partitions containing
the most rows instead:
Added an array of partition ids which is sorted by number of records
in descending order.
this array is used in records_in_range to cover as many records as
possible in as few calls as possible.
Also changed the limit of how many partitions to use for the statistics
from a static max of 10 partitions, into a dynamic model:
Maximum number of partitions is now log2(total number of partitions)
taken from the ordered array.
It will continue calling partitions records_in_range until it has
checked:
(total rows in matching partitions) * (maximum number of partitions)
/ (number of used partitions)
Also reverted the changes for ha_partition::scan_time() and
ha_partition::estimate_rows_upper_bound() to before
the fix of bug#11756867. Since they are not as slow as
records_in_range.
PARTITION STATISTICS
Problem was the fix for bug#11756867; It always used the first
partitions, and stopped after it checked 10 [sub]partitions.
(or until it found a partition which would contain a match).
This results in bad statistics for tables where the first 10 partitions
don't represent the majority of the data (like when the first 10
partitions only contained a few rows in total).
The solution was to take statisics from the partitions containing
the most rows instead:
Added an array of partition ids which is sorted by number of records
in descending order.
this array is used in records_in_range to cover as many records as
possible in as few calls as possible.
Also changed the limit of how many partitions to use for the statistics
from a static max of 10 partitions, into a dynamic model:
Maximum number of partitions is now log2(total number of partitions)
taken from the ordered array.
It will continue calling partitions records_in_range until it has
checked:
(total rows in matching partitions) * (maximum number of partitions)
/ (number of used partitions)
Also reverted the changes for ha_partition::scan_time() and
ha_partition::estimate_rows_upper_bound() to before
the fix of bug#11756867. Since they are not as slow as
records_in_range.
RESULT FROM PREVIOUS TRANSACTION
The current Query Cache API is not fully compatible with
the partitioning engine.
There is no good way to implement support for QC due to:
1) a static callback for ha_partition would need to have access
to all partition names and call the underlying callback for each
[sub]partition with the correct name.
2) pruning would be impossible, even if one used the ulonglong
engine_data due to if engine_data is changed, the table is
invalidated by the QC.
So the only viable solution to avoid incorrect data is to not allow
caching of queries using partitioned tables.
(There are some extra changes, due to removal of \r as line break)
RESULT FROM PREVIOUS TRANSACTION
The current Query Cache API is not fully compatible with
the partitioning engine.
There is no good way to implement support for QC due to:
1) a static callback for ha_partition would need to have access
to all partition names and call the underlying callback for each
[sub]partition with the correct name.
2) pruning would be impossible, even if one used the ulonglong
engine_data due to if engine_data is changed, the table is
invalidated by the QC.
So the only viable solution to avoid incorrect data is to not allow
caching of queries using partitioned tables.
(There are some extra changes, due to removal of \r as line break)
ALTER TABLE AFTER DROP PARTITION
Bug#13608188 - 64038: CRASH IN HANDLER::HA_THD ON ALTER TABLE AFTER
REPAIR NON-EXISTING PARTITION
Backport of bug#13357766 from -trunk to -5.5.
The state of some partitions was not reset on failure, leading
to invalid states of partitions in consequent statements.
Fixed by reverting back to original state for all partitions
if not all partition names was resolved.
Also adding extra security by forcing tables to be reopened
in case of error in mysql_alter_table.
(There is also removal of \r at the end of some lines.)
ALTER TABLE AFTER DROP PARTITION
Bug#13608188 - 64038: CRASH IN HANDLER::HA_THD ON ALTER TABLE AFTER
REPAIR NON-EXISTING PARTITION
Backport of bug#13357766 from -trunk to -5.5.
The state of some partitions was not reset on failure, leading
to invalid states of partitions in consequent statements.
Fixed by reverting back to original state for all partitions
if not all partition names was resolved.
Also adding extra security by forcing tables to be reopened
in case of error in mysql_alter_table.
(There is also removal of \r at the end of some lines.)
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
(also 5.5+ solution for bug#11766879/bug#60106)
The valgrind warning was due to an unused 'new handler_add_index(...)'
which was never freed.
The error handling did not work (fails as in bug#11766879) and
the implementation was not as transparant as it could, therefore I
made it a bit simpler and more transparant to the underlying handlers.
This way it follows the api better and the error handling works and
is also now tested.
Also added a debug test to verify the error handling.
Improved according to Jon Olavs review:
Added class ha_partition_add_index.
Also added base class Sql_alloc to handler_add_index.
Update 3.
(also 5.5+ solution for bug#11766879/bug#60106)
The valgrind warning was due to an unused 'new handler_add_index(...)'
which was never freed.
The error handling did not work (fails as in bug#11766879) and
the implementation was not as transparant as it could, therefore I
made it a bit simpler and more transparant to the underlying handlers.
This way it follows the api better and the error handling works and
is also now tested.
Also added a debug test to verify the error handling.
Improved according to Jon Olavs review:
Added class ha_partition_add_index.
Also added base class Sql_alloc to handler_add_index.
Update 3.
PARTITONING, ON INDEX CREATE
If the first partition succeeded in adding a index, but a successive partition failed,
then the first partition had still the new index.
The fix reverts the added indexes from previous partitions on failure.
PARTITONING, ON INDEX CREATE
If the first partition succeeded in adding a index, but a successive partition failed,
then the first partition had still the new index.
The fix reverts the added indexes from previous partitions on failure.
Split status variable Rows_read to Rows_read and Rows_tmp_read so that one can see how much real data is read.
Same was done with with Handler_update and Handler_write.
Fixed bug in MEMORY tables where some variables was counted twice.
Added new internal handler call 'ha_close()' to have one place to gather statistics.
Fixed bug where thd->open_options was set to wrong value when doing admin_recreate_table()
mysql-test/r/status.result:
Updated test results and added new tests
mysql-test/r/status_user.result:
Udated test results
mysql-test/t/status.test:
Added new test for temporary table status variables
sql/ha_partition.cc:
Changed to call ha_close() instead of close()
sql/handler.cc:
Added internal_tmp_table variable for easy checking of temporary tables.
Added new internal handler call 'ha_close()' to have one place to gather statistics.
Gather statistics for internal temporary tables.
sql/handler.h:
Added handler variables internal_tmp_table, rows_tmp_read.
Split function update_index_statistics() to two.
Added ha_update_tmp_row() for faster tmp table handling with more statistics.
sql/item_sum.cc:
ha_write_row() -> ha_write_tmp_row()
sql/multi_range_read.cc:
close() -> ha_close()
sql/mysqld.cc:
New status variables: Rows_tmp_read, Handler_tmp_update and Handler_tmp_write
sql/opt_range.cc:
close() -> ha_close()
sql/sql_base.cc:
close() -> ha_close()
sql/sql_class.cc:
Added handling of rows_tmp_read
sql/sql_class.h:
Added new satistics variables.
rows_read++ -> update_rows_read() to be able to correctly count reads to internal temp tables.
Added handler::ha_update_tmp_row()
sql/sql_connect.cc:
Added comment
sql/sql_expression_cache.cc:
ha_write_row() -> ha_write_tmp_row()
sql/sql_select.cc:
close() -> ha_close()
ha_update_row() -> ha_update_tmp_row()
sql/sql_show.cc:
ha_write_row() -> ha_write_tmp_row()
sql/sql_table.cc:
Fixed bug where thd->open_options was set to wrong value when doing admin_recreate_table()
sql/sql_union.cc:
ha_write_row() -> ha_write_tmp_row()
sql/sql_update.cc:
ha_write_row() -> ha_write_tmp_row()
sql/table.cc:
close() -> ha_close()
storage/heap/ha_heap.cc:
Removed double counting of statistic variables.
close -> ha_close() to get tmp table statistics.
storage/maria/ha_maria.cc:
close -> ha_close() to get tmp table statistics.
Noted that there was no memory leak, just a lot of used partitioned tables.
Fixed old bug: 'show status' now shows memory usage when compiled with safemalloc.
Added option --flush to mysqlcheck.c to run a 'flush tables' between each check to keep down memory usage.
Changed '--safemalloc' options to mysqld so that one can use --safemalloc and --skip-safemalloc.
Now skip-safemalloc is default (ie, we only do checking of memory overrun during free()) to speed up tests.
client/client_priv.h:
Added OPT_FLUSH_TABLES
client/mysqlcheck.c:
Added option --flush to mysqlcheck.c to run a 'flush tables' between each check to keep down memory usage.
mysql-test/mysql-test-run.pl:
Always run tests with --loose-skip-safemysqld for higher speed
sql/mysqld.cc:
Changed '--safemalloc' options so that one can use --safemalloc and --skip-safemalloc.
Now skip-safemalloc is default (ie, we only do checking of memory overrun during free()) to speed up tests
sql/sql_parse.cc:
Fixed old bug: 'show status' now shows memory usage when compiled with safemalloc.
storage/archive/archive_reader.c:
Changed all malloc() calls to use my_malloc()/my_free()
Added checks of malloc() calls.
storage/archive/ha_archive.cc:
Detect failure if init_archive_reader() and return errno. This fixed assert crash in my_seek().
Changed all malloc() calls to use my_malloc()/my_free()
SECONDARY INDEX IN INNODB
The patches for Bug#11751388 and Bug#11784056 enabled concurrent
reads while creating secondary indexes in InnoDB. However, they
introduced a regression. This regression occured if ALTER TABLE
failed after the index had been added, for example during the
lock upgrade needed to update .FRM. If this happened, InnoDB
and the server got out of sync with regards to which indexes
actually existed. Therefore the patch for Bug#11815600 again
disabled concurrent reads.
This patch re-enables concurrent reads. The original regression
is fixed by splitting the ADD INDEX operation into two parts.
First the new index is created but not made active. This is
done while concurrent reads are allowed. The second part of
the operation makes the index active (or reverts the change).
This is done after lock upgrade, which prevents the original
regression.
In order to implement this change, the patch changes the storage
API for in-place index creation. handler::add_index() is split
into two functions, handler_add_index() and
handler::final_add_index(). The former for creating indexes without
making them visible and the latter for commiting (i.e. making
visible) new indexes or reverting the changes.
Large parts of this patch were written by Marko Mäkelä.
Test case added to innodb_mysql_lock.test.
