What’s new in PoWA 3.0.0

December 7, 2015

Better predicate analyzer

The pg_qualstats (https://github.com/powa-team/pg_qualstats) extension stores new counters. It’s now possible to know the most executed predicates in relation to all the related queries. It also tracks non-normalized queries so that it’s possible to execute an EXPLAIN of any query tracked by pg_stat_statements.

Database global optimization

PoWA is now able to use statistics about every predicate used by any query executed on a database to suggest the smallest index set that optimizes every one of those predicates.

In particular, the heuristics place heavy emphasis in consolidating many indexes into one by giving preference to definitions spanning multiple columns. This can provide new information about the actual load and correlation between predicates that are traditionally hard to discover for the DBA.

Index suggestion check

Thanks to the HypoPG (https://github.com/hypopg/hypoopg) extension, the benefits of the suggested index creations can automatically be checked by running the queries against hypothetical indexes. You can see instantly if the suggested index is relevant and how much it’ll improve the query.


Backward compatibility

  • PoWA 2.0 and later is NOT COMPATIBLE with PostgreSQL 9.3. If you’re using PoWA with PostgreSQL 9.3, you can either keep PoWA 1.2 or upgrade to PostgreSQL 9.4 and switch to PoWA 3.0.0.