On Wed, Oct 30, 2024 at 11:24 AM Don Seiler <don@xxxxxxxxx> wrote: > One thing worth mentioning is that the table is 4 columns, the index is on two of them and includes the other two. I can't think of an explanation for the index being so much larger than its table, especially compared to last month's index. > > Curious if anyone has any thoughts on what might be causing this. You mentioned that this has 4 columns. Sounds like this could be a "locally monotonically increasing index". I wonder if you're benefiting from this optimization, though only inconsistently: https://www.youtube.com/watch?v=p5RaATILoiE&t=2079s https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=f21668f3 Of course, this is only a guess. I vaguely recall a complaint that sounded vaguely like yours, also involving partitioning. -- Peter Geoghegan