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  • MySQL 5.1 Reference Manual :: 12 SQL Statement Syntax :: 12.4 Database Administration Statements :: 12.4.2 Table Maintenance Statements :: 12.4.2.1 ANALYZE TABLE Syntax
    • MySQL 5.1 Reference Manual
    • Preface, Notes, Licenses
    • 1 General Information
    • 2 Installing and Upgrading MySQL
    • 3 Tutorial
    • 4 MySQL Programs
    • 5 MySQL Server Administration
    • 6 Backup and Recovery
    • 7 Optimization
    • 8 Language Structure
    • 9 Internationalization and Localization
    • 10 Data Types
    • 11 Functions and Operators
    • 12 SQL Statement Syntax
    • 13 Storage Engines
    • 14 High Availability and Scalability
    • 15 MySQL Enterprise Monitor
    • 16 Replication
    • 17 MySQL Cluster NDB 6.X/7.X
    • 18 Partitioning
    • 19 Stored Programs and Views
    • 20 INFORMATION_SCHEMA Tables
    • 21 Connectors and APIs
    • 22 Extending MySQL
    • A MySQL 5.1 Frequently Asked Questions
    • B Errors, Error Codes, and Common Problems
    • C MySQL Change History
    • D Restrictions and Limits
    • Index
    • Standard Index
    • C Function Index
    • Command Index
    • Function Index
    • INFORMATION_SCHEMA Index
    • Transaction Isolation Level Index
    • JOIN Types Index
    • Operator Index
    • Option Index
    • Privileges Index
    • SQL Modes Index
    • Status Variable Index
    • Statement/Syntax Index
    • System Variable Index

    12.4.2.1. ANALYZE TABLE Syntax

    ANALYZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE
    tbl_name [, tbl_name] ...

    ANALYZE TABLE analyzes and stores the key distribution for a table. During the analysis, the table is locked with a read lock for MyISAM. For InnoDB the table is locked with a write lock. This statement works with MyISAM and InnoDB tables. For MyISAM tables, this statement is equivalent to using myisamchk --analyze.

    For more information on how the analysis works within InnoDB, see Section 13.6.14, “Restrictions on InnoDB Tables”.

    MySQL Enterprise.  For expert advice on optimizing tables, subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.

    MySQL uses the stored key distribution to decide the order in which tables should be joined when you perform a join on something other than a constant. In addition, key distributions can be used when deciding which indexes to use for a specific table within a query.

    This statement requires SELECT and INSERT privileges for the table.

    Beginning with MySQL 5.1.27, ANALYZE TABLE is also supported for partitioned tables. Also beginning with MySQL 5.1.27, you can use ALTER TABLE ... ANALYZE PARTITION to analyze one or more partitions; for more information, see Section 12.1.7, “ALTER TABLE Syntax”, and Section 18.3.3, “Maintenance of Partitions”.

    ANALYZE TABLE returns a result set with the following columns.

    Column Value
    Table The table name
    Op Always analyze
    Msg_type status, error, info, or warning
    Msg_text An informational message

    You can check the stored key distribution with the SHOW INDEX statement. See Section 12.4.5.23, “SHOW INDEX Syntax”.

    If the table has not changed since the last ANALYZE TABLE statement, the table is not analyzed again.

    By default, ANALYZE TABLE statements are written to the binary log so that they will be replicated to replication slaves. Logging can be suppressed with the optional NO_WRITE_TO_BINLOG keyword or its alias LOCAL.