postgresql - Why aren'y my CHECK CONSTRAINTS on child tables being utilized by the planner to reduce the size of the plan? -
i have table partitioned month , used holding apache log information. when run explain simple query has clause on same field partition checks, same plan whether constraint_exclusion on or off. below master table info , 2 examples of child tables info feb , mar of 2010. overall, there child table each month feb of 2010 through june of 2011. on average, each child table has around 100m records. below output of explain simple query, once constraint_exclusion on , once off. unfortunately, check constraints aren't being used reduce plan size. due fact request_dt datatype timestamp time zone check constraints dates? other thoughts? have not yet created indexes on request_dt, according documentation isn't necessary. i'll adding them, wouldn't think should impact use of check constraints. i'm using postgres 8.3.6. spatial_data=# \d rpt.websvcs_logs table "rpt.websvcs_logs" column | type ...