You need to change your query to not use the trunc. The TRUNC statement forces it to trunc every row in the table. If you do order_date >= to_date(..) and order_date < to_date(..) + interval '1' day, it will use the partition range to narrow down to the correct partition first. Sent from my iPhone > On Aug 24, 2022, at 6:41 PM, Teja Jakkidi <teja.jakkidi05@xxxxxxxxx> wrote: > > Hello Admin team, > > We have a Postgres 13 server set up on Google Cloud. Recently we created partitions as below for the tables: > Range on ‘order_date’ column > List on ‘country_code’ column > > Quarterly partitions for range. > > Order date column is a time stamp column and when we are using this column as a filter in where condition : trunc(order_date) = to_date(’2022-04-01’,’YYYY-MM-DD’), the query scans all the partitions dated back from the year 2000. So, instead of going to the 2022 Q2 partition directly, the query is scanning all the partitions. > But when we remove the trunc() function and just specify order_date =‘2022-04-01 07:02:30’, this works as expected. It goes to the correct partition directly and gets the data. > Can Anyone help me on what’s happening in the first case and why all the partitions are being scanned? > For the first case, when there is a non partition table, it is behaving way better. > > Thanks, > J. Teja. >
