Hi, Some time ago I worked with a database repeating the same sequence of actions multiply times. They're basically: - create table - populate table - do some deletes with some criteria - drop table
After about 20 times I started to notice the usual effects of internal fragmentation (slowness in some usually quick operations and reports of large seek from VFS). I assume this has something to do with the way new pages allocated from free list. I narrowed it to a little test that can reproduce this (tested with 3.7.10) CREATE TABLE [TestTable] ([Id] INTEGER PRIMARY KEY AUTOINCREMENT) Insert into TestTable Default Values /* do this 1,000,000 times */ Delete from TestTable where (Id/1000) % 2 = 0 Drop table TestTable This test makes the db very fragmented after about 10 steps. I thought recently that the main source of internal fragmentation is the nature of the data added. But looks like not only. Even if your data is sequential, but the free_list is fragmented, then you would probably get fragmented internal data. Is it possible to automatically sort free_list from time to time? Or maybe some other solution if this would cost too much? Thanks Max _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
