Holger Jakobs <holger@xxxxxxxxxx> writes: > Am 07.12.23 um 19:11 schrieb Rajesh Kumar: >> Will pg_dump cause blocking queries? If so how to take dump without >> blocking? > Readers don't block writers, writers don't block readers in PostgreSQL. > pg_dump is a reader. To enlarge on that a bit: pg_dump takes AccessShareLock on every table it intends to dump. This does not conflict with ordinary DML updates. It *will* conflict with anything that wants AccessExclusiveLock, which typically is schema-altering DDL. See https://www.postgresql.org/docs/current/explicit-locking.html#LOCKING-TABLES So the answer to your question is "don't try to alter the database schema while pg_dump is running". You can alter database content freely, though. regards, tom lane
