Re: DWH varchar2(4000)

From: <>
Date: Tue, 23 Dec 2014 10:15:54 +0200
Message-ID: <>

What about "ORA-01450: maximum key length (6398 - or more, depends on block size) exceeded" when indexing such columns ?

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From:	Ricard Martinez <>
To:	"" <>,
Date:	2014.12.22 17:03
Subject:	DWH varchar2(4000)
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Hi list,

We have a DWH database on
The developers/data modelers are creating all the tables with varchar2 (4000) as standard by default. They don't care if they just insert 10 bytes, 200  or nothing.
When asked about why this standard is in place, the answer is just: "Just in case we need it".

For my point of view this is not a good practice, as can cause memory waste on client applications, as well as data garbage or errors like ORA-01450: maximum key length (3218) exceeded.

But as i'm not a DWH expert, maybe im missing information that proves that this is really a good practice, and not just a laziness way of working.

I will be glad to know your opinion, or point me to any doc/test that proves me wrong, in order to learn about this.



Received on Tue Dec 23 2014 - 09:15:54 CET

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