RE: Processing new rows in staging table quickly...

From: Reen, Elizabeth <"Reen,>
Date: Thu, 18 Apr 2019 14:35:24 +0000
Message-ID: <f93a5bbad97c479c9c091710d5363140_at_imcnam.ssmb.com>

                Staging tables should always be cleaned up.  Otherwise they grow and get unwieldy.

Liz

From: [External] oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> On Behalf Of [External] Neil Chandler Sent: Thursday, April 18, 2019 6:22 AM
To: post.ethan_at_gmail.com; niall.litchfield_at_gmail.com Cc: ORACLE-L <oracle-l_at_freelists.org> Subject: Re: Processing new rows in staging table quickly...

I agree about not overloading the date column and also was wondering why there's data being left in the staging table.

If the PROCESSED column has a default of 'N', and you update that to NULL to mean processed it keeps the index very small and efficient. Remember to document/comment that NULL means processed! Failing that, make sure you have a frequency histogram on the PROCESSED column.

Neil.

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From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> <oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>> on behalf of niall.litchfield_at_gmail.com<mailto:niall.litchfield_at_gmail.com> <niall.litchfield_at_gmail.com<mailto:niall.litchfield_at_gmail.com>> Sent: 18 April 2019 09:44
To: post.ethan_at_gmail.com<mailto:post.ethan_at_gmail.com> Cc: ORACLE-L
Subject: Re: Processing new rows in staging table quickly...

The FBI approach will work just fine. Personally, I'd probably do one of the following:

• add a "PROCESSED" column accepting 'Y' or 'N' and index/query on that, Mostly for human readability.
• ask, if this is a "staging" table why are there ever any "processed" rows left in it.

On Thu, Apr 18, 2019 at 12:33 AM <post.ethan_at_gmail.com<mailto:post.ethan_at_gmail.com>> wrote:

I have a staging table in which 99% of the rows are going to have a date for stats_processed_time.

I will need to only select for rows that have not been processed.

What is the best strategy here? Should I allow nulls and select like below? Or should I put a date, way out in the future, say 2099, and select for that instead and then update to correct data once things are processed? Perhaps allow nulls and a bitmap or FBI solution (I would like to avoid solutions which can't be ported to Postgres.)

...

where b.access_key=v_access_key

       and b.bucket=v_bucket

       and b.stats_processed_time is null

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Niall Litchfield
Oracle DBA
http://www.orawin.info<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.orawin.info&d=DwMF-g&c=j-EkbjBYwkAB4f8ZbVn1Fw&r=yWMFosURAngbt8VLeJtKLVJGefQxustAZ9UxecV7xpc&m=mvNR112CPT81d7wzQi8ZlOve3BX8yJbEPGJ75mVrpu0&s=5kPvdtx7NNWd2rHRZy66IXxXdzA_St5reaaNxbPk7OA&e=>

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http://www.freelists.org/webpage/oracle-l Received on Thu Apr 18 2019 - 16:35:24 CEST