On Thu, Apr 28, 2016 at 5:53 PM, Richard Hipp <drh at sqlite.org> wrote:
> > It looks like the ENABLE_STAT2/STAT4 options generate histogram data > which > > would probably help for non-uniform data? > > Yes, STAT4 provides histogram data to help with query planning on > tables with non-uniform data distributions. STAT4 is a compile-time > option that is off by default, because it has the disadvantage of > breaking the Query Planner Stability Guarantee Richard, is STAT3 or STAT4 required for https://www.sqlite.org/optoverview.html#skipscan ? Or essential for skip-scan to bring the most benefit? --DD
