PolarDB:Kernel versions 5.6, 5.7, and 8.0

Supported major versions

Standards and protocols

Examples

Example 1: SHOW CREATE TABLE

When you create a table with a GLOBAL index, SHOW CREATE TABLE wraps the keyword in a versioned comment:

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;

Result:

| 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 */ |

Example 2: mysqldump

mysqldump preserves versioned comments in its output. When the dump is imported into standard MySQL, MySQL silently ignores the PolarDB-specific syntax.

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 */
/*!*/;
......

Example 3: Binary log synchronization

This example synchronizes binary logs 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 details, see From a PolarDB for MySQL cluster to an ApsaraDB RDS for MySQL instance.

2. View the binary log synchronization result on both systems. Sample result on PolarDB for MySQL 8.0.2.2.0: Sample result on MySQL 8.0.27: PolarDB-specific features do not appear in the MySQL result.

After synchronization, PolarDB-specific features (such as GLOBAL indexes) are no longer available on the MySQL side.

Manually adding versioned comments for other DDL statements

SHOW CREATE TABLE and mysqldump add versioned comments automatically for CREATE TABLE statements. For other DDL statements, add the comment manually:

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

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 */