Are any of these improvements specifically in the area of the online backup
API, or are they more in the general running of SQLite?

On 20 September 2014 11:14, Richard Hipp <> wrote:

> The latest SQLite 3.8.7 alpha version (available on the download page
> is 50% faster than the 3.7.17 release
> from 16 months ago.  That is to say, it does 50% more work using the same
> number of CPU cycles.
> This performance gain is over and above the query planner improvements that
> have also been made.  We are constantly looking for new ways to run queries
> and adding those ways into the query planner.  For example, in the previous
> release, we added a new way to evaluate IN operators with non-constant
> right-hand-sides that was reported on this mailing list to make some
> queries run 5 times faster.
> The 50% faster number above is not about better query plans.  This is 50%
> faster at the low-level grunt work of moving bits on and off disk and
> search b-trees.  We have achieved this by incorporating hundreds of
> micro-optimizations.  Each micro-optimization might improve the performance
> by as little as 0.05%.  If we get one that improves performance by 0.25%,
> that is considered a huge win.  Each of these optimizations is unmeasurable
> on a real-world system (we have to use cachegrind to get repeatable
> run-times) but if you do enough of them, they add up.
> A full 10% of the performance gain has come since the previous release.
> There have been a lot of changes.  All our tests pass, and we still have
> 100% branch test coverage, so we are confident that we didn't break too
> much.  But your testing is an important part of our quality process.
> Please download a source archive or a DLL and give the latest alpha a
> whirl, and let us know if you encounter any problems.
> P.S.:  Measurements were done using the "speedtest1 --size 5" workload on
> Ubuntu 10.13 and gcc 4.8.1 with -Os.  YMMV.  Version 3.7.17 requires
> 1432835574 CPU cycles and the 3.8.7 alpha requires just 953861485 CPU
> cycles, as measured by cachegrind.
> --
> D. Richard Hipp
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