PG_LOCKS¶
PG_LOCKS displays information about the locks held by open transactions.
Name | Type | Reference | Description |
|---|---|---|---|
locktype | text |
| Type of the locked object: relation, extend, page, tuple, transactionid, virtualxid, object, userlock, and advisory |
database | oid | PG_DATABASE.oid | OID of the database in which the locked target exists
|
relation | oid | PG_CLASS.oid | OID of the relationship targeted by the lock. The value is NULL if the object is neither a relationship nor part of a relationship. |
page | integer |
| Page number targeted by the lock within the relationship. If the object is neither a relation page nor row page, the value is NULL. |
tuple | smallint |
| Row number targeted by the lock within the page. If the object is not a row, the value is NULL. |
virtualxid | text |
| Virtual ID of the transaction targeted by the lock. If the object is not a virtual transaction ID, the value is NULL. |
transactionid | xid |
| ID of the transaction targeted by the lock. If the object is not a transaction ID, the value is NULL. |
classid | oid | PG_CLASS.oid | OID of the system table that contains the object. If the object is not a general database object, the value is NULL. |
objid | oid |
| OID of the lock target within its system table. If the target is not a general database object, the value is NULL. |
objsubid | smallint |
| Column number for a column in the table. The value is 0 if the target is some other object type. If the object is not a general database object, the value is NULL. |
virtualtransaction | text |
| Virtual ID of the transaction holding or awaiting this lock |
pid | bigint |
| Logical ID of the server thread holding or awaiting this lock. This is NULL if the lock is held by a prepared transaction. |
mode | text |
| Lock mode held or desired by this thread For more information, see "LOCK" in the Data Warehouse Service (DWS) SQL Syntax Reference. |
granted | boolean |
|
|
fastpath | boolean |
| Whether the lock is obtained through fast-path (true) or main lock table (false) |