1
0
mirror of https://github.com/MariaDB/server.git synced 2025-12-09 08:01:34 +03:00
Files
mariadb/mysql-test
Mattias Jonsson 42282c10ce Bug#13694811: THE OPTIMIZER WRONGLY USES THE FIRST INNODB
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.
2012-02-22 23:13:36 +01:00
..
2011-10-03 13:41:59 +02:00
2011-06-30 17:37:13 +02:00
2011-07-03 17:47:37 +02:00
2012-01-31 17:39:40 +05:30
2010-12-28 19:57:23 +01:00

This directory contains a test suite for the MySQL daemon. To run
the currently existing test cases, simply execute ./mysql-test-run in
this directory. It will fire up the newly built mysqld and test it.

Note that you do not have to have to do "make install", and you could
actually have a co-existing MySQL installation. The tests will not
conflict with it.

All tests must pass. If one or more of them fail on your system, please
read the following manual section for instructions on how to report the
problem:

http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html

If you want to use an already running MySQL server for specific tests,
use the --extern option to mysql-test-run. Please note that in this mode,
the test suite expects you to provide the names of the tests to run.
For example, here is the command to run the "alias" and "analyze" tests
with an external server:

mysql-test-run --extern alias analyze

To match your setup, you might also need to provide --socket, --user, and
other relevant options.

With no test cases named on the command line, mysql-test-run falls back
to the normal "non-extern" behavior. The reason for this is that some
tests cannot run with an external server.


You can create your own test cases. To create a test case, create a new
file in the t subdirectory using a text editor. The file should have a .test
extension. For example:

 xemacs t/test_case_name.test

 In the file, put a set of SQL statements that create some tables,
 load test data, and run some queries to manipulate it.

 We would appreciate it if you name your test tables t1, t2, t3 ... (to not
 conflict too much with existing tables).

 Your test should begin by dropping the tables you are going to create and
 end by dropping them again.  This ensures that you can run the test over
 and over again.
 
 If you are using mysqltest commands (like result file names) in your
 test case, you should create the result file as follows:

 mysql-test-run --record test_case_name

 or

 mysqltest --record < t/test_case_name.test

 If you only have a simple test cases consisting of SQL statements and
 comments, you can create the test case in one of the following ways:

 mysql-test-run --record test_case_name

 mysql test < t/test_case_name.test > r/test_case_name.result

 mysqltest --record --record-file=r/test_case_name.result < t/test_case_name.test

 When this is done, take a look at r/test_case_name.result
 - If the result is incorrect, you have found a bug. In this case, you should
   edit the test result to the correct results so that we can verify
   that the bug is corrected in future releases.

To submit your test case, put your .test file and .result file(s) into
a tar.gz archive, add a README that explains the problem, ftp the 
archive to ftp://support.mysql.com/pub/mysql/secret/ and send a mail
to bugs@lists.mysql.com