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https://issues.apache.org/jira/browse/TRAFODION-2010?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15569583#comment-15569583
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David Wayne Birdsall commented on TRAFODION-2010:
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This is a duplicate of JIRA TRAFODION-1253 and JIRA TRAFODION-25.
In JIRA TRAFODION-25, I added costing code for insert and delete. I did the
insert code first and I don't think it is very good code. The delete code is
better.
There is some shared code between update and delete (they share a class; some
methods are used for both). In doing the update code it is probably best to
keep this, and to follow the example for delete.
> UPDATE/DELETE cannot generate a parallel plan properly
> ------------------------------------------------------
>
> Key: TRAFODION-2010
> URL: https://issues.apache.org/jira/browse/TRAFODION-2010
> Project: Apache Trafodion
> Issue Type: Bug
> Reporter: liu ming
> Assignee: Yang, Yongfeng
>
> For big UPDATE/DELETE, that is, affecting a lot of rows, for example, 10M
> rows to update, Trafodion cannot generate a proper parallel plan by default.
> So very slow.
> Reproduce steps:
> DDL
> CREATE TABLE T113B
> (
> UNIQ INT NO DEFAULT NOT NULL
> , C100K INT DEFAULT NULL
> , C10K INT DEFAULT NULL
> , C1K INT DEFAULT NULL
> , C100 INT DEFAULT NULL
> , C10 INT DEFAULT NULL
> , C1 INT DEFAULT NULL
> , C0 INT DEFAULT NULL ,
> Primary key(uniq)
> )
> SALT USING 80 PARTITIONS
> ATTRIBUTES ALIGNED FORMAT
> ;
>
> Populate data:
> upsert using load into t113b select
> 0 + (100000 * x100000) + (10000 * x10000) + (1000 * x1000) +
> (100 * x100) + (10 * x10) +( 1 * x1),
> 0 + (10000 * x10000) + (1000 * x1000) + (100 * x100) +
> (10 * x10) +( 1 * x1),
> 0 + (1000 * x1000) + (100 * x100) + (10 * x10) + (1 * x1),
> 0 + (100 * x100) + (10 * x10) + (1 * x1),
> 0 + (10 * x10) + (1 * x1),
> 0 + (1 * x1),
> 0,
> X0
> from (values(0)) t
> transpose 0,1,2,3,4,5,6,7,8,9 as x100000
> transpose 0,1,2,3,4,5,6,7,8,9 as x10000
> transpose 0,1,2,3,4,5,6,7,8,9 as x1000
> transpose 0,1,2,3,4,5,6,7,8,9 as x100
> transpose 0,1,2,3,4,5,6,7,8,9 as x10
> transpose 0,1,2,3,4,5,6,7,8,9 as x1
> transpose 0,1,2,3,4,5,6,7,8,9 as x0;
>
> The update DML
> explain options 'f' update t113b set c0 = 0 where c1 = 0;
> DELETE is similar.
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