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pg_locks
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pg_locks [2018/12/08 00:22] |
pg_locks [2020/06/13 13:46] (текущий) |
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| + | ====== pg_locks блокировки в PostgreSQL ====== | ||
| + | {{htmlmetatags> | ||
| + | metatag-description=(Представление pg_locks даёт доступ к информации о блокировках, | ||
| + | }} | ||
| + | |||
| + | * [[http:// | ||
| + | * [[PostgreSQL]] | ||
| + | * [[postgresql# | ||
| + | |||
| + | Представление (VIEW) pg_locks содержит подробную информацию о блокировках в базе данных. Список текущих блокировок с указанием типа блокировки, | ||
| + | |||
| + | Один из распространенных случаев, | ||
| + | select l.database, d.datname, l.relation, c.relname, | ||
| + | l.locktype, | ||
| + | l.virtualxid, | ||
| + | l.pid, l.mode, l.granted, | ||
| + | c.relacl | ||
| + | from pg_locks as l | ||
| + | LEFT JOIN pg_database AS d ON l.database= d.oid | ||
| + | LEFT JOIN pg_class AS c ON l.relation = c.oid | ||
| + | order by c.relname; | ||
| + | </ | ||
| + | select pg_class.relname, | ||
| + | pg_locks.virtualtransaction, | ||
| + | from pg_class, | ||
| + | where pg_class.relfilenode = pg_locks.relation | ||
| + | order by pg_class.relname; | ||
| + | </ | ||
| + | ====== Запросы ====== | ||
| + | ^^Name^Type^References^Description^^^^ | ||
| + | ||locktype|text| |type of the lockable object: relation, extend, page, tuple, transactionid, | ||
| + | ||database|oid|pg_database.oid|OID of the database in which the object exists, or zero if the object is a shared object, or NULL if the object is a transaction ID|OID базы данных, | ||
| + | ||relation|oid|pg_class.oid|OID of the relation, or NULL if the object is not a relation or part of a relation|||| | ||
| + | ||page|integer| |Page number within the relation, or NULL if the object is not a tuple or relation page|||| | ||
| + | ||tuple|smallint| |Tuple number within the page, or NULL if the object is not a tuple|||| | ||
| + | ||virtualxid|text| |Virtual ID of a transaction, | ||
| + | ||transactionid|xid| |ID of a transaction, | ||
| + | ||classid|oid|pg_class.oid|OID of the system catalog containing the object, or NULL if the object is not a general database object|||| | ||
| + | ||objid|oid|any OID column|OID of the object within its system catalog, or NULL if the object is not a general database object|||| | ||
| + | ||objsubid|smallint| |For a table column, this is the column number (the classid and objid refer to the table itself). For all other object types, this column is zero. NULL if the object is not a general database object|||| | ||
| + | ||virtualtransaction|text| |Virtual ID of the transaction that is holding or awaiting this lock|||| | ||
| + | ||pid|integer| |Process ID of the server process holding or awaiting this lock. NULL if the lock is held by a prepared transaction|Идентификатор процесса в ОС соответствует выводу команды [[ps]], например: | ||
| + | ||mode|text| |Name of the lock mode held or desired by this process|Текстовое описание [[postgresql# | ||
| + | ||granted|boolean| |True if lock is held, false if lock is awaited|Значение t (true) значит установлена, | ||
| + | |||
| + | < | ||
| + | # select * from pg_locks; | ||
| + | locktype | ||
| + | ------------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+------+-----------------+--------- | ||
| + | | ||
| + | | ||
| + | | ||
| + | | ||
| + | | ||
| + | |||
| + | </ | ||
