Does a SELECT COUNT(*) on a PostgreSQL table lock it?

Question

Does performing a SELECT COUNT(*) on a PostgreSQL table lock it? If so is there a way around it to behave like WITH (nolock) in SQL Server?

Answer 1

No.

A SELECT never locks a table in Postgres.

Or more precisely: it only takes a very weak shared lock that prevents DDL on the table.

In Postgres, readers never block writers and writers never block readers.