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[selva21]

Hi,

SELECT FROM TABLE1
WHERE
FIELD_1:=VAR-1 AND/OR
FIELD_2:=VAR-2 AND/OR
FIELD_3:=VAR-3

There are indexes available on columns FIELD_1 and FIELD_2. No index on FIELD_3.

In this scenario, DB2 will go for a Indexspace scan or Tablespace scan?

Thanks,
Selva.
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Knowledge is power. But Imagination is more important than Knowledge. -Albert Einstein
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[bauer]

Hi selva21,

this depends on your query, are you using AND or OR, could depend on cadinality of table.

Is the index on FILED_1 only or FIELD_2 only , or both ? How many different values are available for FIELD_1and FIELD_2 ?

Use EXPLAIN command to find out, what DB2 will do !

regards,
bauer

[selva21]

Thanks Bauer !

We are in the process of deciding a strategy for Adabas to DB2 migration.

Is there any document/manual available that speaks on how DB2 decides to go for Tablescan/Indexscan?

Thanks,
Selva.
_________________
--------------------------------------------------------
Knowledge is power. But Imagination is more important than Knowledge. -Albert Einstein
--------------------------------------------------------