Duan Ligong wrote:
> I mean I want to estimate the size of the space which the db will occupy.
> Now there is no db.
With a bit of math and the info here -
http://www.postgresql.org/docs/8.3/interactive/storage-page-layout.html
you can start to get an idea.
Simple calculation would be 23 bytes overhead per row + length of data
in columns with one or two extra overhead on some types (like length of
string or array) also don't forget that text may be more than one byte
per char.
A similar estimate for indexes can come into play as well.
The final size will likely be a bit larger as you also get issues like
data alignment and unused space on a page that doesn't fit a row...
--
Shane Ambler
pgSQL (at) Sheeky (dot) Biz
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