diff --git a/information-schema/information-schema-data-lock-waits.md b/information-schema/information-schema-data-lock-waits.md index c6a31fb4a315f..0244ac7b3f03e 100644 --- a/information-schema/information-schema-data-lock-waits.md +++ b/information-schema/information-schema-data-lock-waits.md @@ -89,3 +89,7 @@ CURRENT_HOLDING_TRX_ID: 426790590082449409 ``` The above query result shows that the transaction of the ID `426790594290122753` is trying to obtain the pessimistic lock on the key `"7480000000000000355F728000000000000001"` when executing a statement that has digest `"38b03afa5debbdf0326a014dbe5012a62c51957f1982b3093e748460f8b00821"` and is in the form of ``update `t` set `v` = `v` + ? where `id` = ?``, but the lock on this key was held by the transaction of the ID `426790590082449409`. + +### See also + +- [Troubleshooting lock conflicts](/troubleshoot-lock-conflicts.md) \ No newline at end of file diff --git a/mysql-schema/mysql-schema.md b/mysql-schema/mysql-schema.md index 96d9adba68921..976ec5761cece 100644 --- a/mysql-schema/mysql-schema.md +++ b/mysql-schema/mysql-schema.md @@ -84,7 +84,7 @@ Currently, the `help_topic` is NULL. ## System tables related to metadata locks -* `tidb_mdl_view`: a view of metadata locks. You can use it to view information about the currently blocked DDL statements +* `tidb_mdl_view`: a view of metadata locks. You can use it to view information about the currently blocked DDL statements. See also [Metadata Lock](/metadata-lock.md) * `tidb_mdl_info`: used internally by TiDB to synchronize metadata locks across nodes ## System tables related to DDL statements diff --git a/troubleshoot-lock-conflicts.md b/troubleshoot-lock-conflicts.md index fc1399896168c..a04bbdb74427a 100644 --- a/troubleshoot-lock-conflicts.md +++ b/troubleshoot-lock-conflicts.md @@ -159,6 +159,12 @@ In the above query, the [`TIDB_DECODE_SQL_DIGESTS`](/functions-and-operators/tid If the `start_ts` of the current transaction is unknown, you can try to find it out from the information in the `TIDB_TRX` / `CLUSTER_TIDB_TRX` table or in the [`PROCESSLIST` / `CLUSTER_PROCESSLIST`](/information-schema/information-schema-processlist.md) table. +### Metadata locks + +When a session is waiting on a schema change this can be because of a metadata lock. + +See [Metadata locks](/metadata-lock.md) for more information. + ## Troubleshoot optimistic lock conflicts This section provides the solutions of common lock conflict issues in the optimistic transaction mode.