tdsql [(none)]> SELECT * FROM performance_schema.data_locks \\G
*************************** 1. row ***************************
                             ENGINE: RocksDB
                     ENGINE_LOCK_ID: 28681376014270466_(0000279780000006,00002798)
              ENGINE_TRANSACTION_ID: 28681376014270466
                          THREAD_ID: 44
                           EVENT_ID: NULL
                      OBJECT_SCHEMA: testdb
                        OBJECT_NAME: test
                     PARTITION_NAME: NULL
                  SUBPARTITION_NAME: NULL
                         INDEX_NAME: NULL
              OBJECT_INSTANCE_BEGIN: 140502282795216
                          LOCK_TYPE: PRE_RANGE
                          LOCK_MODE: Write
                        LOCK_STATUS: GRANTED
                          LOCK_DATA: NULL
                          START_KEY: 0000279780000006
                            END_KEY: 00002798
                  EXCLUDE_START_KEY: 1
           BLOCKING_TRANSACTION_NUM: 0
BLOCKING_CHECK_READ_TRANSACTION_NUM: 0
                    READ_LOCKED_NUM: 0
                          TINDEX_ID: 10135
                    DATA_SPACE_TYPE: DATA_SPACE_TYPE_USER
               REPLICATION_GROUP_ID: 257
                KEY_RANGE_REGION_ID: 7312
                     PROCESSLIST_ID: 2097282
                            NODE_ID: 2
                          NODE_NAME: node-1-002
*************************** 2. row ***************************
                             ENGINE: RocksDB
                     ENGINE_LOCK_ID: 28681376014270466_0000279780000006
              ENGINE_TRANSACTION_ID: 28681376014270466
                          THREAD_ID: 44
                           EVENT_ID: NULL
                      OBJECT_SCHEMA: testdb
                        OBJECT_NAME: test
                     PARTITION_NAME: NULL
                  SUBPARTITION_NAME: NULL
                         INDEX_NAME: NULL
              OBJECT_INSTANCE_BEGIN: 140507882943448
                          LOCK_TYPE: KEY
                          LOCK_MODE: Write
                        LOCK_STATUS: GRANTED
                          LOCK_DATA: NULL
                          START_KEY: NULL
                            END_KEY: 0000279780000006
                  EXCLUDE_START_KEY: 0
           BLOCKING_TRANSACTION_NUM: 0
BLOCKING_CHECK_READ_TRANSACTION_NUM: 0
                    READ_LOCKED_NUM: 0
                          TINDEX_ID: 10135
                    DATA_SPACE_TYPE: DATA_SPACE_TYPE_USER
               REPLICATION_GROUP_ID: 257
                KEY_RANGE_REGION_ID: 7312
                     PROCESSLIST_ID: 1048704
                            NODE_ID: 1
                          NODE_NAME: node-1-001

-- 查询所有节点的悲观锁数量
SELECT COUNT(*) FROM performance_schema.data_locks \\G

-- 查询所有节点上，replication group 257 的 key range region 7312 的所有的悲观锁信息（仅指定 key_range_region_id 也可查询，但效率较差，无法利用索引加速查询）
SELECT * FROM performance_schema.data_locks WHERE replication_group_id = 257 AND key_range_region_id = 7312 \\G

-- 查询所有节点上，和 [0000279780000003, 0000279780000004] 有交集的所有悲观锁的信息
SET @left = "0000279780000003";
SET @right = "0000279780000004";
SELECT * FROM performance_schema.data_locks WHERE
	(lock_type = 'KEY' AND @left <= end_key AND end_key <= @right) OR -- 如果是单条 key 上的悲观锁，那么对应的 key 存储在 end_key 字段上，只要 end_key 在区间内即可
    (lock_type = 'PRE_RANGE' AND @left < end_key AND (start_key < @right OR (NOT exclude_start_key and start_key = @right))) \\G -- 如果是 key 区间上的悲观锁，那么需要根据 exclude_start_key，判断 [start_key, end_key) 或 (start_key, end_key) 和区间是否有交集

-- 查询所有节点上，testdb.test 表所有悲观锁的信息
-- 第一步：获取 testdb.test 的 tindex_id
SELECT tindex_id FROM information_schema.statistics WHERE table_schema = 'testdb' AND table_name = 'test';
-- 第二步：使用第一步获取到的 tindex_id 查询锁信息
SELECT * FROM performance_schema.data_locks WHERE tindex_id = 12345;

-- 或直接使用tableName databaseName查询相关悲观锁信息
SELECT * FROM performance_schema.data_locks WHERE OBJECT_SCHEMA = 'testdb' AND OBJECT_NAME = 'test';

-- 查询所有节点上，事务 28681535313936395 所加所有悲观锁的信息
SELECT * FROM performance_schema.data_locks WHERE engine_transaction_id = 28681535313936395 \\G

-- 查询所有节点上，阻塞了事务的所有悲观锁的信息
SELECT * FROM performance_schema.data_locks WHERE blocking_transaction_num > 0 OR blocking_check_read_transaction_num > 0 

BEGIN;
SELECT a FROM t FOR UPDATE;
SELECT SLEEP(100);

SELECT b FROM t FOR UPDATE;

SELECT c FROM t FOR UPDATE;