pg有没有alter session set ddl_lock_timeout=xxx这种操作?

name | setting | unit | category | short_desc | extra_desc | context | vartype | source | min_val | max_val | enumvals | boot_val | reset_val | sourcefile | sourceline | pending_restart -------------------------------------+---------+------+--------------------------------------------------------------+-------------------------------------------------------------------------------------------+-------------------------------------+-----------+---------+---------+---------+------------+----------+----------+-----------+------------+------------+----------------- archive_timeout | 0 | s | Write-Ahead Log / Archiving | Forces a switch to the next WAL file if a new file has not been started within N seconds. | | sighup | integer | default | 0 | 1073741823 | | 0 | 0 | | | f authentication_timeout | 60 | s | Connections and Authentication / Security and Authentication | Sets the maximum allowed time to complete client authentication. | | sighup | integer | default | 1 | 600 | | 60 | 60 | | | f checkpoint_timeout | 300 | s | Write-Ahead Log / Checkpoints | Sets the maximum time between automatic WAL checkpoints. | | sighup | integer | default | 30 | 86400 | | 300 | 300 | | | f deadlock_timeout | 1000 | ms | Lock Management | Sets the time to wait on a lock before checking for deadlock. | | superuser | integer | default | 1 | 2147483647 | | 1000 | 1000 | | | f idle_in_transaction_session_timeout | 0 | ms | Client Connection Defaults / Statement Behavior | Sets the maximum allowed duration of any idling transaction. | A value of 0 turns off the timeout. | user | integer | default | 0 | 2147483647 | | 0 | 0 | | | f lock_timeout | 0 | ms | Client Connection Defaults / Statement Behavior | Sets the maximum allowed duration of any wait for a lock. | A value of 0 turns off the timeout. | user | integer | default | 0 | 2147483647 | | 0 | 0 | | | f statement_timeout | 0 | ms | Client Connection Defaults / Statement Behavior | Sets the maximum allowed duration of any statement. | A value of 0 turns off the timeout. | user | integer | default | 0 | 2147483647 | | 0 | 0 | | | f wal_receiver_timeout | 60000 | ms | Replication / Standby Servers | Sets the maximum wait time to receive data from the primary. | | sighup | integer | default | 0 | 2147483647 | | 60000 | 60000 | | | f wal_sender_timeout | 60000 | ms | Replication / Sending Servers

使用alter system set　或者 set xxx=xxx;
保证排他锁不冲突，大表加字段是很快的