Re: Load and Query question

Mladen,

> In data warehouse situation, you don't have to prevent data from entering,
> data is
> already checked and trusted, you are extracting data from your OLTP
> database, ..

I'd love to operate a DW above your OLTP. In my experience I sow a lot of systems where the data is only trusted.

> You must index your DW properly. Indexing schemes are widely described
> in various books.

paradoxically from the point of view of loading data in DW with full refresh (as discussed in this thread) the best indexing schema is the empty one as

• the indices needn't be refreshed on load (with or without APPEND)
• don't get invalid on partition exchange (this is getting better in newer releases)
• don't need to be reanalysed
• optimizer is not tempted to start NL with large loops

etc.

Of course those that are performing query of the data in DW see this a little different:)

Regards,

Jaromir

• Original Message ----- From: "Mladen Gogala" <gogala_at_sbcglobal.net> To: <shreeni_at_sbcglobal.net> Cc: "'Oracle Discussion List'" <oracle-l_at_freelists.org> Sent: Thursday, April 27, 2006 5:44 PM Subject: Re: Load and Query question

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