#MYSQL OPTIMIZER STATISTICS UPDATE#
#MYSQL OPTIMIZER STATISTICS MANUAL#
#MYSQL OPTIMIZER STATISTICS FULL#

It is possible to run ANALYZE on the slave, and then take the data from statistics tables on the slave and apply it on the master.

#MYSQL OPTIMIZER STATISTICS FULL#

ANALYZE TABLE does a full table scan, which can put too much load on the server. Running ANALYZE on a different server.Currently, the ANALYZE TABLE command will collect the statistics, but there is no special command to delete statistics.

#MYSQL OPTIMIZER STATISTICS UPDATE#

One way to force all tables to be re-opened is to issue FLUSH TABLES command.ДЄ few scenarios where one might need to update statistics tables manually: Statistics data will be re-read when the tables are re-opened. One should modify the table(s) with regular INSERT/ UPDATE/ DELETE statements. It is possible to update statistics tables manually.

#MYSQL OPTIMIZER STATISTICS MANUAL#

SET SESSION use_stat_tables = 'COMPLEMENTARY' ANALYZE TABLE tbl Manual Updates to Statistics Tables ) - the following will only update mysql.table_stats fields: ANALYZE TABLE tbl PERSISTENT FOR COLUMNS () INDEXES () - when use_stat_tables is set to 'COMPLEMENTARY' or 'PREFERABLY', - a simple ANALYZE TABLE collects engine-independent statistics for all columns and indexes.

) INDEXES () ANALYZE TABLE tbl PERSISTENT FOR COLUMNS () INDEXES ( idx1, idx2. ) - empty lists are allowed: ANALYZE TABLE tbl PERSISTENT FOR COLUMNS ( col1, col2. Examples of Statistics Collection - update all engine-independent statistics for all columns and indexes ANALYZE TABLE tbl PERSISTENT FOR ALL - update specific columns and indexes: ANALYZE TABLE tbl PERSISTENT FOR COLUMNS ( col1, col2. If a column using one of these types is explicitly specified, then a warning is returned. Statistics for columns using the BLOB and TEXT data types are not collected.

The ANALYZE TABLE statement includes the PERSISTENT FOR clause.

The use_stat_tables system variable is set to complementary or preferably.Engine-independent statistics will only be collected by the ANALYZE TABLE statement if one of the following is true: The specific behavior depends on the value of the use_stat_tables system variable. When the ANALYZE TABLE statement is executed, MariaDB may also collect engine-independent statistics for the table. For InnoDB, see InnoDB Persistent Statistics for more information. The specific behavior depends on the storage engine. When the ANALYZE TABLE statement is executed, MariaDB makes a call to the table's storage engine, and the storage engine collects its own statistics for the table. The ANALYZE TABLE statement can be used to collect table statistics.

Available and default from MariaDB 10.4.1.Д¬ollecting Statistics with the ANALYZE TABLE Statement Same as preferably, but for queries only (to avoid needlessly collecting for ANALYZE TABLE). Same as complementary, but for queries only (to avoid needlessly collecting for ANALYZE TABLE). Prefer the data from statistics tables, if it's not available there, use the data from the storage engine. The optimizer uses data from statistics tables if the same kind of data is not provided by the storage engine. The optimizer doesn't use data from statistics tables. Use or update of data from these tables is controlled by use_stat_tables variable. Statistics are stored in three tables, mysql.table_stats, lumn_stats and mysql.index_stats.

it is possible for a DBA to read and update the values.

Statistics are stored in regular tables in the mysql database.

There was no way to 'pin' current statistic values, or provide some values on your own, etc.Д®ngine-independent table statistics lift these limitations.

There was little control of the statistics.

The statistics were supplied through the MySQL Storage Engine Interface, which puts a lot of restrictions on what kind of data is supplied (for example, there is no way to get any data about value distribution in a non-indexed column).

Storage engines provided poor statistics (this wasДЇixed to some degree with the introduction of Persistent Statistics).

This approach worked however it had some deficiencies: InnoDB) to provide statistics for the query optimizer.

Collecting Statistics for Specific Columns or IndexesД«efore MariaDB 10.0, the MySQL/MariaDB optimizer relied on storage engines (e.g.

Collecting Statistics with the ANALYZE TABLE Statement.

Mysql optimizer statistics