如何优化更新语句

Question

我正在 MySQL 中维护 Mike Hillyer 分层数据。

Q) 如何优化下面的更新语句。平均需要大约 500 毫秒

update AGENCY_TREE set RGT = RGT - 2  where RGT > 2;

该表包含大约 15k 数据。结构如下

CREATE TABLE IF NOT EXISTS `user_tree` (
  `USER_ID` bigint NOT NULL COMMENT 'The user ID',
  `LFT` bigint NOT NULL COMMENT 'Left boundary of all children',
  `RGT` bigint NOT NULL COMMENT 'Right boundary of all children',
  PRIMARY KEY (`USER_ID`),
  UNIQUE KEY `U_USER_TREE_LFT` (`LFT`),
  UNIQUE KEY `U_USER_TREE_RGT` (`RGT`),
  CONSTRAINT `FK_USER_TREE_AGENCY` FOREIGN KEY (`USER_ID`) REFERENCES `agency` (`USER_ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='USER hierachy tree';