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 <d...@sqlite.org> wrote: > The latest SQLite 3.8.7 alpha version (available on the download page > http://www.sqlite.org/download.html) 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 > d...@sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
