3 ms·

How much of a slowdown did you estimate this bug caused?

• devoutsalsa 2y ago
  90%?
• metadat 2y ago
  It actually would have performed faster, but the false positive rate drastically increased.
  • LudwigNagasena 2y ago
    I guess the person is asking how much a slowdown did the whole query receive.
• jschafer 2y ago
  SQLite only knows nested loop joins and the bloom filter can just tell us "no need to do a join, there is definitely no matching entry". If it has a false positive all the time (the worst case) then the performance is the same as before the bloom filter optimization was implemented (besides the small bloom filter overhead). As the bloom filter size in SQLite directly depends on the table size I estimated a false positive rate of 63.2% due to this bug, while it could have been just 11.75%.