Hi,
We have a SAPDB 7.3.0 BUILD 043-000, database,
I am having performance problems on this database, I have noticed the
following, when I have for instance a table like the following with the
first five columns as part of the primary key.
Table : Test
Columns
Test1 - Primary Key
Test2 - Primary Key
Test3 - Primary Key
Test4 - Primary Key
Test5 - Primary Key
Test6
Test7
Test8
.......
If I have a SQL as follows,
Select *
>From Test
Where Test1 = 'A' and Test2 = 'B' and Test3 = 'C' and Test4 = 'D' and
Test5 = 'E'
Then the optimizer will use all the key columns and the select will be
quite fast, if I change the SQL to the following
Select *
>From Test
Where Test1 = 'A' and Test2 = 'B' and Test3 IN ('C','D') and Test4 =
'E' and Test5 = 'F'
Then the optimizer will only use Test1 and Test2, and scan through the
rest of the table!
This does not seem right to me, can't the optimizer still use the rest
of the key columns?
The same happens when the IN statement is changed to a ( OR ) statement!
Is there perhaps a parameter I can change to allow the optimizer to
function across a IN statement?
Thanks,
Robert
