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Message Posted: Fri, 10 Feb 2006 @ 15:32:18 GMT

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To my knowledge, I don't believe you can Union within a Join Index.

You might benefit from Horizontal Partitioning more than you would a Join Index if your meet the following criteria:

1) You can use a 'Union All' instead of 'Union'

2) Some values within a shared column exists (or can be derived and physically materialized as a new column) that would seperate these tables (for instance, splitting a year's worth of data into 12 tables by month)

3) You anticipate that most queries will only access a subset of the tables

4) You anticipate that most queries will be able to specify (literally) the partitioning value (such as a sepcific month)

Assuming you are OK with these 4 assumption (and you are on V2R5), you will need to add a physical constraint in each of these tables specifying the specific partition value(s) for each table:

For instance:

     Alter table Test_DB.Test_Tbl
     Add Constraint Test_Constraint Check (Rpt_Mth_Cd = 200501);

Hope this helps,

Clay

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