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Message Posted: Fri, 20 Jun 2003 @ 00:45:16 GMT
I work with federated systems.
I did a sample test: I created two tables with the same datas (integer, char), 100 rows each, in each data sources (DB2, Oracle, Sybase, MsSql, Teradata etc...) and do a simple join between the two table.
And I compare explain plans.
After, I executed "collect statistics on column" then "collect statistics on table" . I re populated my nickname. I compare the new explain plans, but for Teradata, nothing has changed!!! Teradata after gathering statistics still thinks I have 1000 rows (I only inserted 100 rows).
Could you explain me why teradata doesn t collect the statistics? Why everything is equal before and after collect statistics?
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