On 02/04/2018 11:14 AM, Mariel Cherkassky wrote: > > Hi, > I configured range partitions on a date column of my main > table(log_full). Each partition represents a day in the month. Every day > partition has a list parition of 4 tables on a text column. > > log_full > log_full_01_11_2017 --> > log_full _01_11_2017_x1 > log_full _01_11_2017_x2 > log_full _01_11_2017_x3 > log_full _01_11_2017_x4 > log_full_02_11_2017 > log_full _02_11_2017_x1 > log_full _02_11_2017_x2 > log_full _02_11_2017_x3 > log_full _02_11_2017_x4 > > and so on.... > > > The date column consist of date in the next format : YYYY-MM-DD HH:24:SS > for example : 2017-11-01 00:01:40 > > I wanted to check the plan that I'm getting for a query that is using > the date column and it seems that the planner choose to do seq scans on > all tables. > > -Each partition consist from 15M rows. > I have about 120 partitions. > > The query : > explain select count(*) from log_full where end_date between > to_date('2017/12/03','YY/MM/DD') and to_date('2017/12/03','YY/MM/DD'); > > The output is too long but it do full scans on all paritions... > any idea what can be the problem? Is it connected to the date format ? > You haven't shown us how the partitions are defined, nor the query plan. So it's rather hard to say. You mentioned text format, but then you use to_date() to query the partitioned table. Which I guess might be the cause, but it's hard to say for sure. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services