On Wed, Dec 7, 2022 at 12:09 PM Aleksander Alekseev < aleksan...@timescale.com> wrote: > > Hi hackers, > > A colleague of mine reported a slight inconvenience with pg_dump. > > He is dumping the data from a remote server. There are several > thousands of tables in the database. Making a dump locally and/or > using pg_basebackup and/or logical replication is not an option. So > what pg_dump currently does is sending LOCK TABLE queries one after > another. Every query needs an extra round trip. So if we have let's > say 2000 tables and every round trip takes 100 ms then ~3.5 minutes > are spent in the not most useful way. > > What he proposes is taking the locks in batches. I.e. instead of: > > LOCK TABLE foo IN ACCESS SHARE MODE; > LOCK TABLE bar IN ACCESS SHARE MODE; > > do: > > LOCK TABLE foo, bar, ... IN ACCESS SHARE MODE; > > The proposed patch makes this change. It's pretty straightforward and > as a side effect saves a bit of network traffic too. >
+1 for that change. It will improve the dump for databases with thousands of relations. The code LGTM and it passes in all tests and compiles without any warning. Regards, -- Fabrízio de Royes Mello
