Re: Bigger block sizes

From: Mark Brinsmead <mark.brinsmead_at_gmail.com>
Date: Thu, 1 Oct 2015 22:32:55 -0600
Message-ID: <CAAaXtLA5WYdX3LE55J95aRmWyXQyaEf20peEU1hSMR31-L7bow_at_mail.gmail.com>

One (sort of) legitimate use-case I came across was an inherited database where they used tablespaces with 32KB blocks to house indexes that required insanely huge keys.

(Even with 32KB blocks, we were sometimes unable to create the indexes we wanted/needed, which often included multiple VARCHAR(4000) columns.)

The application itself was highly unusual, and the underlying architecture even more so. (And I had nothing whatsoever to do with either of them.)

Anyway, cases where you truly need indexes with really large keys will warrant block sizes greater than 8KB. With 8KB blocks, you are limited to something like 3916 bytes as your largest key. (Yes, I know -- that ought to be enough for most people. Did I mention that I had no input into the architectural decisions?)

On Wed, Sep 30, 2015 at 3:29 PM, Orlando L <oralrnr_at_gmail.com> wrote:

> List,
>
> Does anyone in the list use non default blocksize of greater than 8K for
> your oracle DBs; if so, is it for warehousing/OLAP type applications? What
> advantages do you get with them; any disadvantage.
>
> Orlando.
>

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Received on Fri Oct 02 2015 - 06:32:55 CEST