On 28/03/2010 10:07 AM, Tadipathri Raghu wrote:
Hi All,
I want to give some more light on this by analysing more like this
1. In my example I have created a table with one column as INT( which
occupies 4 bytes)
2. Initially it occupies one page of space on the file that is (8kb).
So, here is it assuming these many rows may fit in this page. Clarify
me on this Please.
Like I said, it's just a guess. With no statistics all postgres can do
is guess, or in this case use the in-built default for a newly created
table. It could guess 1 or it could guess 10,000,000. What it does is
produce a reasonable guess in the absence of any other information.
You should read the postgres documentation for further information about
statistics and how the optimizer uses them.
Regards,
Gary.
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