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Archives of the TeradataForum
Message Posted: Thu, 25 Apr 2002 @ 16:05:12 GMT
| Subj: | | Group-AMPs Retrieve |
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| From: | | Anomy Anom |
<-- Anonymously Posted: Thursday, April 25, 2002 11:53 -->
Can anyone explain what group-AMPs RETRIEVE means in step 5 of this explain? In my select statement, I am selecting my the primary index
but I have an OR clause on field SPL_EXT_NO, which would explain steps 2 & 3.
Thanks.
Explanation
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| | 1) | First, we lock corpdbp1.CIRCUIT3T for access.
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| | 2) | Next, we do a single-AMP RETRIEVE step from corpdbp1.CIRCUIT3T by way of the primary index "corpdbp1.CIRCUIT3T.SPL_MODIFIER = '1 ',
corpdbp1.CIRCUIT3T.SPL_PREFIX = '1 ' , corpdbp1.CIRCUIT3T.SPL_CO_ASGN = 'ATI ', corpdbp1.CIRCUIT3T.SPL_SER_NO = 1 ,
corpdbp1.CIRCUIT3T.SPL_SUFFIX = '1 ', corpdbp1.CIRCUIT3T.SPL_SVC_CODE = 'DH' , corpdbp1.CIRCUIT3T.SPL_CENT_OFF = NULL,
corpdbp1.CIRCUIT3T.SPL_EXT_NO = ' ' , corpdbp1.CIRCUIT3T.SPL_LINE_NO = NULL, corpdbp1.CIRCUIT3T.SPL_NPA = NULL" extracting row ids only with
no residual conditions into Spool 2, which is built locally on that AMP. The size of Spool 2 is estimated to be 15 rows. The estimated
time for this step is 0.03 seconds.
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| | 3) | We do a single-AMP RETRIEVE step from corpdbp1.CIRCUIT3T by way of the primary index "corpdbp1.CIRCUIT3T.SPL_MODIFIER = '1 ',
corpdbp1.CIRCUIT3T.SPL_PREFIX = '1 ' , corpdbp1.CIRCUIT3T.SPL_CO_ASGN = 'ATI ', corpdbp1.CIRCUIT3T.SPL_SER_NO = 1 ,
corpdbp1.CIRCUIT3T.SPL_SUFFIX = '1 ', corpdbp1.CIRCUIT3T.SPL_SVC_CODE = 'DH' , corpdbp1.CIRCUIT3T.SPL_CENT_OFF = NULL,
corpdbp1.CIRCUIT3T.SPL_EXT_NO = NULL , corpdbp1.CIRCUIT3T.SPL_LINE_NO = NULL, corpdbp1.CIRCUIT3T.SPL_NPA = NULL" extracting row ids only
with no residual conditions into Spool 2, which is built locally on that AMP. The size of Spool 2 is estimated to be 30 rows. The
estimated time for this step is 0.03 seconds.
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| | 4) | We do a SORT to order Spool 2 by row id eliminating duplicate rows. The estimated time for this step is 0.00 seconds.
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| | 5) | We do a group-AMPs RETRIEVE step from corpdbp1.CIRCUIT3T by way of row ids from Spool 2 (Last Use) with a residual condition of
("(corpdbp1.CIRCUIT3T.SPL_NPA IS NULL) AND ((corpdbp1.CIRCUIT3T.SPL_LINE_NO IS NULL) AND (((corpdbp1.CIRCUIT3T.SPL_EXT_NO IS NULL) OR
(corpdbp1.CIRCUIT3T.SPL_EXT_NO = ' ')) AND ((corpdbp1.CIRCUIT3T.SPL_CENT_OFF IS NULL) AND ((corpdbp1.CIRCUIT3T.SPL_CO_ASGN = 'ATI ') AND
((corpdbp1.CIRCUIT3T.SPL_SUFFIX = '1 ') AND ((corpdbp1.CIRCUIT3T.SPL_SER_NO = 1) AND ((corpdbp1.CIRCUIT3T.SPL_MODIFIER = ' 1 ') AND
((corpdbp1.CIRCUIT3T.SPL_SVC_CODE = 'DH') AND (corpdbp1.CIRCUIT3'1')))))))))") into Spool 1, which is built locally on the AMPs. The size
of Spool 1 is estimated with low confidence to be 30 rows. The estimated time for this step is 0.28 seconds.
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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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| | -> | The contents of Spool 1 are sent back to the user as the result of statement 1. The total estimated time is 0.34 seconds.
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