Dozens of micro-optimizations result in 6.7% fewer CPU cycles needed
to do the same amount work. (Measured using
cachegrind on the
speedtest1.c workload on
Ubuntu 13.10 x64 with gcc 4.8.1 and -Os. Your performance may vary.)
Provide the ability for the sorter to start and use auxiliary helper threads in order
to increase real-time response. This feature is off by default and may be
enabled using the PRAGMA threads command or the SQLITE_DEFAULT_WORKER_THREADS
Enhance the skip-scan optimization so that it is able to skip index terms that
occur in the middle of the index, not just as the left-hand side of the index.
The query planner is now able to do a better job of understanding constants that
occur inside of CAST operators.