Jens Páll Hafsteinsson wrote: > Closing and opening again did not speed up steps 1-4, it actually slowed > things down even more. The curve from the beginning is a bit similar to a > slightly flattened log curve. When I closed the database and started the test > again, a similar curve appeared again, but now starting from where the first > run left off. > > I've been running the same 3.6.15 since this afternoon (the previous test was > using 3.6.14) and it seems to flatten out fairly quickly but it is > significantly slower (2.3 to 1.3 times slower, depending on where you measure > it using the data I have). I'm not that worried about that for the time > being; I'm just hoping it will stay flat. > > JP > > > > On 16 Jun 2009, at 1:06pm, Jens Páll Hafsteinsson wrote: > > >> 1. start a transaction >> >> 2. insert 1000 records >> >> 3. commit >> >> 4. repeat steps 1-3 100 times >> >> 5. delete everything from the table >> >> 6. Start again at step 1 >> > > Jens,
Can you post the schema for your table and the index (i.e. the actual schema you are using for the test), and also the code that shows how you are assigning values to the columns in your table when you do the inserts? I suspect that you may be using a autoincrement id field and then running into the extra work (both CPU load and increased disk space) needed to handle the variable sized integer storage method used by SQLite. This would lead to the type of logarithmic growth you are seeing. The first few iterations used short single byte integer values, the next bunch use 2 byte integer values, etc. The autoincrement field would cause SQLite to continue at the same speed after restarting the application as you have described, since the next field values used would continue from where it left off at the end of the previous run. I would have expected the time to stabilize on 3 byte values fairly qucikly, and then only change again when switching to values that required 4 bytes. This may be a part of the answer even if it is not the complete answer. Dennis Cote _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
