Horton

Re: [SQL] 6.4.x vs. 6.5 oddity

Ross J. Reedstrom <reedstrm@wallace.ece.rice.edu>

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From: reedstrm@wallace.ece.rice.edu (Ross J. Reedstrom)
To: pierre@desertmoon.com
Cc: pgsql-sql@postgreSQL.org
Date: 1999-03-08T19:53:02Z
Lists: pgsql-sql 
Pierre - 
Are you sure the databases are identical? Including indicies? The only
significant difference I can see is the choice of index by the 6.5 plan
for the scan on pcat:

> V6.5
>  Index Scan using pcat_dcat_id_idx on pcat c  (cost=264.24 size=4465 width=4)
> 
> V6.4
>  Index Scan using pcat_prod_id_idx on pcat c  (cost=2.00 size=4457 width=4)

Strangely enough, the estimated total cost difference is about the same ratio.


-- 
Ross J. Reedstrom, Ph.D., <reedstrm@rice.edu> 
NSBRI Research Scientist/Programmer
Computer and Information Technology Institute
Rice University, 6100 S. Main St.,  Houston, TX 77005