Обсуждение: pg_dump blocking create database?

My PG server came to a screeching halt yesterday.  Looking at top saw a very
large number of "startup waiting" tasks.   A pg_dump was running and one of my
scripts had issued a CREATE DATABASE command.  It looks like the CREATE DATABASE
was exclusive but was having to wait for the pg_dump to finish, causing a
massive traffic jam of locks behind it.

Once I killed the pg_dump process, things returned to normal.

Version 8.0.12.  Is this a bug? It also concerns me because my workload is
likely to expose this problem again.

Dan Harris <fbsd@drivefaster.net> writes:
> My PG server came to a screeching halt yesterday.  Looking at top saw a very
> large number of "startup waiting" tasks.   A pg_dump was running and one of my
> scripts had issued a CREATE DATABASE command.  It looks like the CREATE DATABASE
> was exclusive but was having to wait for the pg_dump to finish, causing a
> massive traffic jam of locks behind it.

> Once I killed the pg_dump process, things returned to normal.

> Version 8.0.12.  Is this a bug?

It's operating as designed :-(.  8.1 and later use less strict locking
on pg_database during create/drop database.

            regards, tom lane