Hi, On 2016-11-13 23:04:44 +0000, James Sewell said: > 1. INSERT ... SELECT doesn't work > 2. WITH a AS (SELECT ...) INSERT FROM a doesn't work > 3. SELECT .. INTO doesn't work > 4. SELECT with no insert does work as expected >> >> CREATE TABLE blah AS SELECT ... ?
Unfortunately, in these cases the current parallelism features cannot be used as all of these queries do write data. See in the doc [1] at "When Can Parallel Query Be Used?" > Even when it is in general possible for parallel query plans to be generated, > the planner will not generate them for a given query if any of the following > are true: > • The query writes any data or locks any database rows. If a > query contains a data-modifying operation either at the top level or within a > CTE, no parallel plans for that query will be generated. This is a limitation > of the current implementation which could be lifted in a future release. Best Tobias [1]: https://www.postgresql.org/docs/current/static/when-can-parallel-query-be-used.html -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
