PolarDB：Engine versions 5.6, 5.7, and 8.0

A complete engine version number of PolarDB for MySQL consists of three parts: the major version (DB version) number, the minor version number, and the revision version number. The following figure shows the relationship among the three parts, using PolarDB for MySQL version 8.0 as an example.

Alibaba Cloud provides release notes for each engine version. The release notes include new features, modified features, and fixed issues. For more information, see the following topics:

• PolarDB for MySQL 8.0.2

• PolarDB for MySQL 8.0.1

• PolarDB for MySQL 5.7

• PolarDB for MySQL 5.6

The following section provides the compatibility information of PolarDB for MySQL engine versions:

• Complies with ANSI and ISO SQL standards. You can set the sql_mode parameter of your cluster to ANSI to enable the ANSI session mode. For more information about how to modify the cluster parameters, see Specify cluster and node parameters.

• Supports Open Database Connectivity (ODBC) versions from 0 to 3.51.

• Supports XML features that comply with W3C and XPath standards.

• PolarDB for MySQL 5.7 and 8.0 support the native JSON data types that comply with RFC 7159 and ECMA-262 standards.

The following table lists the compatibility between PolarDB for MySQL engine versions and MySQL community editions.

To ensure that PolarDB for MySQL is compatible with the CREATE TABLE statement, you can use the SHOW CREATE TABLE statement, mysqldump tool, and binary log synchronization to automatically add the CREATE TABLE statement. Take note of the following items:

• Method 1: Execute the SHOW CREATE TABLE statement. Example:

  CREATE TABLE `t1` (c1 int, KEY(c1) GLOBAL) ENGINE=InnoDB PARTITION BY HASH (`c1`) PARTITIONS 4;
  Query OK, 0 rows affected (0.06 sec)
  
  SHOW CREATE TABLE t1;
  +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
  | Table | Create Table                                                                                                                                                                                                         |
  +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
  | t1    | CREATE TABLE `t1` (
    `c1` int(11) DEFAULT NULL,
    KEY `c1` (`c1`) /*!99990 800020207 GLOBAL */
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
  /*!50100 PARTITION BY HASH (`c1`)
  PARTITIONS 4 */ |

• Method 2: Use the mysqldump tool. Example:

  CREATE TABLE `t1` (c1 int, KEY(c1) GLOBAL) ENGINE=InnoDB PARTITION BY HASH (`c1`) PARTITIONS 4;
  DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci PARTITION BY HASH (`c1`);
  --result
  mysqldump --compact test t1
  
  include/mysqlbinlog.inc
  /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
  /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
  DELIMITER /*!*/;
  ROLLBACK/*!*/;
  # [empty]
  # original_commit_timestamp= MICROSECONDS-FROM-EPOCH (YYYY-MM-DD HOURS:MINUTES:SECONDS TZ)
  # immediate_commit_timestamp= MICROSECONDS-FROM-EPOCH (YYYY-MM-DD HOURS:MINUTES:SECONDS TZ)
  /*!80001 SET @@session.original_commit_timestamp= MICROSECONDS-FROM-EPOCH*//*!*/;
  /*!80014 SET @@session.original_server_version= ORIGINAL_SERVER_VERSION*//*!*/;
  /*!80014 SET @@session.immediate_server_version= IMMEDIATE_SERVER_VERSION*//*!*/;
  SET @@SESSION.GTID_NEXT= '#'/*!*/;
  use `test`/*!*/;
  SET TIMESTAMP=#/*!*/;
  SET @@session.pseudo_thread_id=#/*!*/;
  SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
  SET @@session.sql_mode=1168113696/*!*/;
  SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
  /*!\C utf8mb4 *//*!*/;
  SET @@session.character_set_client=255,@@session.collation_connection=255,@@session.collation_server=255/*!*/;
  SET @@session.lc_time_names=0/*!*/;
  SET @@session.collation_database=DEFAULT/*!*/;
  /*!80011 SET @@session.default_collation_for_utf8mb4=255*//*!*/;
  /*!80013 SET @@session.sql_require_primary_key=0*//*!*/;
  CREATE TABLE `t1` (
    `c1` int(11) DEFAULT NULL,
    KEY `c1` (`c1`) /*!99990 800020207 GLOBAL */
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
  /*!50100 PARTITION BY HASH (`c1`)
  PARTITIONS 4 */
  /*!*/;
  ......

• Method 3: Use binary log synchronization.

  In the following example, binary logs are synchronized from PolarDB for MySQL 8.0.2.2.0 to MySQL 8.0.27.

  1. Use Data Transmission Service (DTS) to synchronize binary logs from PolarDB for MySQL 8.0.2.2.0 to MySQL 8.0.27. For more information, see Synchronize data from a PolarDB for MySQL cluster to an ApsaraDB RDS for MySQL instance.

  2. View the binary log synchronization result on PolarDB for MySQL 8.0.2.2.0 and MySQL 8.0.27.

     Sample result on PolarDB for MySQL 8.0.2.2.0:

     Sample result on MySQL 8.0.27: As shown in the preceding figures, the new features provided in PolarDB for MySQL do not appear in the MySQL result.

     Note

     After data is synchronized from PolarDB for MySQL 8.0.2.2.0 to MySQL 8.0.27, the new features provided in PolarDB for MySQL are no longer available in MySQL.

For DDL statements other than CREATE TABLE, you must manually add comments to PolarDB for MySQL statements to ensure compatibility. Syntax:

/*!99990 800020200 Special new PolarDB Syntax SQL supported >= version 2.2.0 */

Example:

CREATE TABLE `t1` (
`c1` int(11) DEFAULT NULL,
KEY `c1` (`c1`) /*!99990 800020207 GLOBAL */
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
/*!50100 PARTITION BY HASH (`c1`)
PARTITIONS 4 */