See http://www.postgresql.org/docs/current/static/storage-page-layout.html for all of what is taking up the space. Short version: Per block overhead is > 24 bytes Per row overhead is 23 bytes + some alignment loss + the null bitmap if you have nullable columns
On Mon, Mar 29, 2010 at 8:24 AM, raghavendra t <raagavendra....@gmail.com>wrote: > Hi Mattew, > > Thank you for the information. > > Once again, I like to thank each and everyone in this thread for there > ultimate support. > > Regards > Raghavendra > > On Mon, Mar 29, 2010 at 4:47 PM, Matthew Wakeling <matt...@flymine.org>wrote: > >> On Mon, 29 Mar 2010, Tadipathri Raghu wrote: >> >>> As per the documentation, one page is 8kb, when i create a table with int >>> as >>> one column its 4 bytes. If i insert 2000 rows, it should be in one page >>> only >>> as its 8kb, but its extending vastly as expected. Example shown below, >>> taking the previous example table test with one column. >>> >> >> There is more to a row than just the single int column. The space used by >> a column will include a column start marker (data length), transaction ids, >> hint bits, an oid, a description of the types of the columns, and finally >> your data columns. That takes a bit more space. >> >> Matthew >> >> -- >> If you let your happiness depend upon how somebody else feels about you, >> now you have to control how somebody else feels about you. -- Abraham >> Hicks >> >> -- >> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org >> ) >> To make changes to your subscription: >> http://www.postgresql.org/mailpref/pgsql-performance >> > >
