> > OK, so your tables all have the same fields (columns), as if you used > CREATE TABLE new_table ( LIKE some_template_table ) ?
It will contain some other unique columns for each table. > meaning that they contain NULL values in that field for every record? what is the value it may contain i don't know ?? we are not filling any value !! > > > If you drop those columns we will gain any performance or not..... > I need to test... HOW to test the overall performance of database.. > However, I recall hearing that PostgreSQL keeps a null bitmap and doesn't > use any storage for null fields. If that is correct then you probably won't > be paying much of a price in disk I/O, but there might still be other costs. > if it is sure that it will not make disk I/O then it is ok > > I can't help wondering why you have all those useless columns in the > first place, and why you have so many identically structured tables. > these are not useless columns... it should be used to update the owner of the record, updated time, created and other stuffs, but nobody is using now. > > -- > Craig Ringer >