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Archives of the TeradataForum
Message Posted: Tue, 12 Feb 2002 @ 16:49:31 GMT
| Subj: | | Re: Insert data into table |
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| From: | | Andres Del Villar |
Our tables have only UPI. I deleted statistics because i need to know if the process is better or worse than tables with statistics. I
know that the statistics are usefull for client-queries, but in my particular case, and only in this moment, i'm testing several choices for
resolve my problem.
The explain for one on our queries is
INSERT INTO ventas.talineadetalle
SELECT *
FROM temporal.talineadetalletemp
Explanation
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| | 1) | First, we lock a distinct Temporal."pseudo table" for read on a RowHash to prevent global deadlock for Temporal.taLineaDetalleTemp.
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| | 2) | Next, we lock a distinct Ventas."pseudo table" for write on a RowHash to prevent global deadlock for Ventas.taLineaDetalle.
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| | 3) | We lock Temporal.taLineaDetalleTemp for read, and we lock Ventas.taLineaDetalle for write.
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| | 4) | We do an all-AMPs RETRIEVE step from Temporal.taLineaDetalleTemp by way of an all-rows scan with no residual conditions into Spool 1,
which is built locally on the AMPs. Then we do a SORT to order Spool 1 by row hash. The size of Spool 1 is estimated with low confidence
to be 237,492 rows. The estimated time for this step is 1 minute and 37 seconds.
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| | 5) | We do a MERGE into Ventas.taLineaDetalle from Spool 1 (Last Use).
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| | 6) | Finally, we send out an END TRANSACTION step to all AMPs involved in processing the request.
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| | -> | No rows are returned to the user as the result of statement 1.
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This table have only a UPI
This sentence take around 50 minutes and insert only 300.000 rows app.
adelv
DBA - FASA
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