PolarDB:Limits of global secondary indexes on DML

Prerequisites

The versions of the custom ApsaraDB RDS for MySQL instances are 5.7 or later, and the versions of the PolarDB-X 1.0 instances are 5.4.1 or later.

Examples

The following table is used to describe the limits that GSIs have on DML.

CREATE TABLE t_order(
  `id` bigint(11) NOT NULL AUTO_INCREMENT,
  `order_id` varchar(20) DEFAULT NULL,
  `buyer_id` varchar(20) DEFAULT NULL,
  `seller_id` varchar(20) DEFAULT NULL,
  `order_snapshot` longtext DEFAULT NULL,
  `order_detail` longtext DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `l_i_order` (`order_id`),
  GLOBAL INDEX `g_i_seller` (`seller_id`) dbpartition by hash(`seller_id`) tbpartition by hash(`seller_id`),
  GLOBAL UNIQUE INDEX `g_i_buyer` (`buyer_id`) COVERING (order_snapshot) dbpartition by hash(`buyer_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 dbpartition by hash(`order_id`);

After a GSI fails to be written to a table, other DML statements cannot be executed on the table and transactions cannot be committed on the table.

SET DRDS_TRANSACTION_POLICY='XA';
INSERT INTO t_order(order_id, buyer_id, seller_id) VALUES('order_1', 'buyer_1', 'seller_1');
# A GSI failed to be written to the table.
INSERT IGNORE INTO t_order(order_id, buyer_id, seller_id) VALUES('order_2', 'buyer_1', 'seller_1');
# Other DML statements cannot be executed on the table.
INSERT IGNORE INTO t_order(order_id, buyer_id, seller_id) VALUES('order_2', 'buyer_2', 'seller_2');
# Transactions cannot be committed on the table.
COMMIT;