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.
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Craig Ringer