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Re: Inheritance

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Hasnul Fadhly bin Hasan <hasnulfadhly(dot)h(at)mimos(dot)my>
Cc: pgsql-novice(at)postgresql(dot)org
Subject: Re: Inheritance
Date: 2004-12-21 03:45:26
Message-ID: 2188.1103600726@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-novice
Hasnul Fadhly bin Hasan <hasnulfadhly(dot)h(at)mimos(dot)my> writes:
> I'm just wondering, what real benefit does inheritance have?  When i 
> create two tables, one inherited from the other,
> does that mean i have two tables with same duplicate data or actually 
> they are joined in the back end?

It's more like an implicit UNION ALL.  There's no duplication, but when
you specify a SELECT/UPDATE/DELETE over the parent table, the child
table is implicitly processed as well.

			regards, tom lane

In response to

  • Inheritance at 2004-12-21 03:21:55 from Hasnul Fadhly bin Hasan

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