IV> I've spent a long time debugging low performance of an IV> application that uses :memory: database and have found IV> that sqlite v2 is much faster than v3. After some IV> digging around it seems that even two proof-of-concept IV> programs that are identical except for used SQLite IV> version reproduce this behaviour just fine:
>> ./sqlite3_bench IV> 2564 qps >> ./sqlite_bench IV> 20000 qps IV> (that's queries per second) IV> I've attached the source of these two programs, but in IV> case the attachments get stripped: all they do is open IV> a database, create a simple table with 3 fields, set IV> one of them as primary key and add a index on another IV> field, then insert 100,000 dummy records. IV> Approximately the same situation is for a test that IV> selects 100,000 records from this database one by one, IV> only sqlite3 is about 2x faster in this case (sqlite3: IV> 6000 qps, sqlite2: 20000 qps). IV> Is this a "known behaviour"? Should I stick to using IV> sqlite2 for memory databases? Two questions: Does it only happen with a :memory: database or even if you use a file? With version of the v3 lib did you use? I'm asking because i noticed a similar performance drop (factor 10-15) when i wanted to upgrade my application from 3.2.1 to 3.3.5 Regards, Eric
