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MySQL Cluster 6.1 - 7.1 Release Notes  /  Changes in MySQL Cluster NDB 6.2  /  Changes in MySQL Cluster NDB 6.2.5 (5.1.22-ndb-6.2.5) (2007-09-06, General Availability)

Changes in MySQL Cluster NDB 6.2.5 (5.1.22-ndb-6.2.5) (2007-09-06, General Availability)

This is a bugfix release, fixing recently discovered bugs in the previous MySQL Cluster NDB 6.2 release.

MySQL Cluster NDB 6.2 no longer in development. MySQL Cluster NDB 6.2 is no longer being developed or maintained; if you are using a MySQL Cluster NDB 6.2 release, you should upgrade to the latest version of MySQL Cluster, which is available from .

Obtaining MySQL Cluster NDB 6.2. You can download the latest MySQL Cluster NDB 6.2 source code and binaries for supported platforms from

This Beta release incorporates all bugfixes and changes made in previous MySQL Cluster releases, as well as all bugfixes and feature changes which were added in mainline MySQL 5.1 through MySQL 5.1.22 (see Changes in MySQL 5.1.22 (2007-09-24, Release Candidate)).


Please refer to our bug database at for more details about the individual bugs fixed in this version.

Functionality Added or Changed

  • The following improvements have been made in the utility:

    • The script can now be used with multiple databases; lists of databases and tables can also be excluded from analysis.

    • Schema name information has been added to index table calculations.

    • The database name is now an optional parameter, the exclusion of which causes all databases to be examined.

    • If selecting from INFORMATION_SCHEMA fails, the script now attempts to fall back to SHOW TABLES.

    • A --real_table_name option has been added; this designates a table to handle unique index size calculations.

    • The report title has been amended to cover cases where more than one database is being analyzed.

    Support for a --socket option was also added.

    For more information, see — NDBCLUSTER Size Requirement Estimator. (Bug #28683, Bug #28253)

  • It is now possible to control whether fixed-width or variable-width storage is used for a given column of an NDB table by means of the COLUMN_FORMAT specifier as part of the column's definition in a CREATE TABLE or ALTER TABLE statement.

    It is also possible to control whether a given column of an NDB table is stored in memory or on disk, using the STORAGE specifier as part of the column's definition in a CREATE TABLE or ALTER TABLE statement.

    For permitted values and other information about COLUMN_FORMAT and STORAGE, see CREATE TABLE Syntax.

  • A new cluster management server startup option --bind-address makes it possible to restrict management client connections to ndb_mgmd to a single host and port. For more information, see ndb_mgmd — The MySQL Cluster Management Server Daemon.

  • Online ADD COLUMN, ADD INDEX, and DROP INDEX operations can now be performed explicitly for NDB tables—that is, without copying or locking of the affected tables—using ALTER ONLINE TABLE. Indexes can also be created and dropped online using CREATE INDEX and DROP INDEX, respectively, using the ONLINE keyword.

    You can force operations that would otherwise be performed online to be done offline using the OFFLINE keyword.

    Renaming of tables and columns for NDB and MyISAM tables is performed in place without table copying.

    For more information, see ALTER TABLE Online Operations in MySQL Cluster, CREATE INDEX Syntax, and DROP INDEX Syntax.

  • Cluster Replication: The protocol for handling global checkpoints has been changed. It is now possible to control how often the GCI number is updated, and how often global checkpoints are written to disk, using the TimeBetweenEpochs configuration parameter. This improves the reliability and performance of MySQL Cluster Replication.

    GCPs handled using the new protocol are sometimes referred to as micro-GCPs.

Bugs Fixed

  • When handling BLOB columns, the addition of read locks to the lock queue was not handled correctly. (Bug #30764)

  • Discovery of NDB tables did not work correctly with INFORMATION_SCHEMA. (Bug #30667)

  • A file system close operation could fail during a node or system restart. (Bug #30646)

  • Using the --ndb-cluster-connection-pool option for mysqld caused DDL statements to be executed twice. (Bug #30598)

  • When creating an NDB table with a column that has COLUMN_FORMAT = DYNAMIC, but the table itself uses ROW_FORMAT=FIXED, the table is considered dynamic, but any columns for which the row format is unspecified default to FIXED. Now in such cases the server issues the warning Row format FIXED incompatible with dynamic attribute column_name. (Bug #30276)

  • failed on tables with FLOAT columns whose definitions included commas (for example, FLOAT(6,2)). (Bug #29228)

  • Reads on BLOB columns were not locked when they needed to be to guarantee consistency. (Bug #29102)

    References: See also Bug #31482.

  • A query using joins between several large tables and requiring unique index lookups failed to complete, eventually returning Unknown Error after a very long period of time. This occurred due to inadequate handling of instances where the Transaction Coordinator ran out of TransactionBufferMemory, when the cluster should have returned NDB error code 4012 (Request ndbd time-out). (Bug #28804)

  • An attempt to perform a SELECT ... FROM INFORMATION_SCHEMA.TABLES whose result included information about NDB tables for which the user had no privileges crashed the MySQL Server on which the query was performed. (Bug #26793)

  • Cluster Replication: Cluster replication did not handle large VARCHAR columns correctly. (Bug #29904)

  • Cluster Replication: An issue with the mysql.ndb_apply_status table could cause NDB schema autodiscovery to fail in certain rare circumstances. (Bug #20872)

  • Cluster API: A call to CHECK_TIMEDOUT_RET() in mgmapi.cpp should have been a call to DBUG_CHECK_TIMEDOUT_RET(). (Bug #30681)

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