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Message Posted: Wed, 16 Jul 2003 @ 09:13:16 GMT
<-- Anonymously Posted: Wednesday, July 16, 2003 04:40 -->
We are having a 600GB CALL_HIST table which users query and join it to 10 other tables. Basically they get the Sums of multiple distinct columns and Counts on some columns for Call_Hist table after joining it to the 10 tables.
Now 5 of these tables are Reference type Tables containing only 5 or 6 rows. And looking at the EXPLAIN, all of these joins between the CALL_HIST and the 5 tables were a PRODUCT join. To overcome this and have a better performance I optimised the query by using CASE Statement for those 5/6 values instead of the joins to these tables. Space paucity and other issues have prevented us from building Secondary Indexes or Join Indexes on this table.
Now the users have hit back questioning the logic of having Reference Tables in the Warehouse and complaining CASE is complicated to use. What are your thoughts on this. Have you encountered anything like this before.
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