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postgresqllockingrow

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

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?

Solution

  • 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.