更新时间:2022-09-02 09:26:59
SHOW TOPOLOGY FROM TABLE_NAME
指令获取表拓扑结构。mysql> SHOW TOPOLOGY FROM DRDS_USERS; +------+-------------------+--------------+ | ID | GROUP_NAME | TABLE_NAME | +------+-------------------+--------------+ | 0 | DRDS_00_RDS | DRDS_USERS | | 1 | DRDS_01_RDS | DRDS_USERS | +------+-------------------+--------------+ 2 rows in set (0.06 sec)
/!TDDL:node='DRDS_00_RDS'*/ SELECT * FROM DRDS_USERS;
/!TDDL:node='DRDS_01_RDS'*/ SELECT * FROM DRDS_USERS;
PolarDB-X支持mysqldump指令导出数据。但如果想要更快地扫描数据,可以针对每个分表开启多个会话的方式并行加速扫描。
mysql> SHOW TOPOLOGY FROM LJLTEST; +------+----------------+------------+ | ID | GROUP_NAME | TABLE_NAME | +------+----------------+------------+ | 0 | TDDL5_00_GROUP | ljltest_00 | | 1 | TDDL5_00_GROUP | ljltest_01 | | 2 | TDDL5_00_GROUP | ljltest_02 | | 3 | TDDL5_01_GROUP | ljltest_03 | | 4 | TDDL5_01_GROUP | ljltest_04 | | 5 | TDDL5_01_GROUP | ljltest_05 | | 6 | TDDL5_02_GROUP | ljltest_06 | | 7 | TDDL5_02_GROUP | ljltest_07 | | 8 | TDDL5_02_GROUP | ljltest_08 | | 9 | TDDL5_03_GROUP | ljltest_09 | | 10 | TDDL5_03_GROUP | ljltest_10 | | 11 | TDDL5_03_GROUP | ljltest_11 | +------+----------------+------------+ 12 rows in set (0.06 sec)
如上所示该表有四个分库,每个分库有三个分表。使用以下的SQL对TDDL5_00_GROUP库上的分表进行操作。
/!TDDL:node='TDDL5_00_GROUP'*/ select * from ljltest_00;
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