I first wrote, by mistake, to the sql mailing list. But here is my e-mail:
I wrote a script to make sure all tables are vacuumed and analyzed every evening. This works very well.
I save in a table the start and end time of a vacuum/analyze. This way I can measure what tables take a long time to vaccum/analyze, and what tables are slow. (and much more).
But I have noticed that the parent table of a partitioned table also takes a long time. Here is a snap shot of the following table
table_name ; avg runt time ; max run time ; min run time "f_transaction_1" ; "00:03:07.8" ; "00:03:10" ; "00:03:03" "f_transaction" ; "00:02:19.8" ; "00:02:25" ; "00:02:16"
f_tranaction_1 is 16GB data + 12GB of indexes. (I know, a lot of indexes). f_tranaction is totally empy, but also contains all indexes. Which means 0B table zise, and 140kB index size.
Does anyone has an idea why in this case the vacuum/analyze takes almost as long on the parent table as on the biggest child table? (the other child tables are smaller than f_tranaction_1, and their vacuum/analyze time is much shorter).
