Index-Only Scans: Now There's a Patch

In November of 2010, I blogged about a much-requested PostgreSQL feature: index-only scans.  We've made some progress!  In June of this year, I committed a patch (and then, after Heikki found some bugs, another patch) to make the visibility map crash-safe.  In previous releases, it was possible for the visibility map to become incorrect after a system crash, which means that it could not be relied on for anything very critical.  That should be fixed now.  Last week, I posted a patch for the main feature: index-only scans.

Linux and glibc Scalability

As some of you probably already know from following the traffic on pgsql-hackers, I've been continuing to beat away at the scalability issues around PostgreSQL.  Interestingly, the last two problems I found turned out, somewhat unexpectedly, not to be internal bottlenecks in PostgreSQL.  Instead, they were bottlenecks with other software with which PostgreSQL was interacting during the test runs.