Greetings Lance,
* Campbell, Lance (lance@illinois.edu) wrote:
> In 9.6 if you do a pg_dump on a schema and you have a few very large tables in the schema will this cause the
databaseto lock the table for writing?
In PG, readers do not block writers.
> This is an issue I ran into with older version of PostgreSQL using pg_dump on entire schemas. To get around this
issueI partitioned the really large tables so that the locking would be a much shorter time period while running
pg_dump. But this may not be necessary with 9.6
I'm not sure what issue you ran into, but pg_dump would block someone
from DROP'ing or TRUNACTE'ing a table (or other operations requiring a
very strong lock), not from simply doing an INSERT, UPDATE, or DELETE
(which take a lower lock that doesn't conflict with the locks pg_dump
takes).
Information about the various locks in PG is available here:
https://www.postgresql.org/docs/current/static/explicit-locking.html
Thanks!
Stephen