PostgreSQL 12 Beta 1 Released

In the spirit of the open source PostgreSQL community, we strongly encourage you to test the new features of PostgreSQL 12 in your database systems to help us eliminate any bugs or other issues that may exist. The amount of write-ahead log (WAL) overhead generated when creating a GiST, GIN, or SP-GiST index is also significantly reduced in PostgreSQL 12, which provides several benefits to the disk utilization of a PostgreSQL cluster and features such as continuous archiving and streaming replication. This removes an “optimization fence” that has existed since the introduction of the clause in PostgreSQL 8.4

If need be, you can force a query to materialize using the clause, e.g.

WITH c AS MATERIALIZED ( SELECT * FROM a WHERE a.x % 4 = 0 ) SELECT * FROM c JOIN d ON d.y = a.x;

PostgreSQL 12 improves on the performance when processing tables with thousands of partitions for operations that only need to use a small number of partitions.

Source: www.postgresql.org