I’m currently working on upgrading both the PkgForge build farm and the BuzzSaw log file processor services to SL7.2. Both of these services use PostgreSQL databases and have been stuck on 9.2 for a while pending the server upgrades. The latest version of PostgreSQL (9.6) is due to be released today so I thought I would give the release candidate a whirl to see how I get on. There are numerous benefits over 9.2, in particular I am planning to use the new jsonb column type to store PkgForge build information which was previously serialised to a YAML file, being able to query that data directly from the DB should be very useful. The feature I am most interested in trying from 9.6 is parallel execution of sequential scans, joins and aggregates. This has the potential to make some of the large queries for the BuzzSaw DB much faster. My very simplistic first tests suggest that setting the max_parallel_workers_per_gather option to 4 will reduce the query time by at least 50%, it will need a bit more investigation and analyse to check it really is helpful but that’s an encouraging result.
A 2ndQuadrant blog post has some useful information on the new parallel sequential scan feature.