Re: Why index occupy less amount of space than the table with same structure.

From: Alban Hertroys <dalroi(at)solfertje(dot)student(dot)utwente(dot)nl>
To: Tadipathri Raghu <traghu(dot)dba(at)gmail(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Why index occupy less amount of space than the table with same structure.
Date: 2010-03-28 11:22:27
Message-ID: C87734EA-B114-4E1E-83A2-09043E86E2A9@solfertje.student.utwente.nl
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On 28 Mar 2010, at 10:05, Tadipathri Raghu wrote:

> Hi All,

...

> I like to know here is, I have created a table with one column and the index is on one column only, so why is the space occupied differently, almost all half of the space of the table and why not full. Could please you explain on this. And what exactly the postgres architecture treat on Index table and Ordinary table.

For one thing: The table holds information regarding to which transactions each row is visible (the xid) whereas the index does not.

Alban Hertroys

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