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[CZerfas]

I have a pretty komplex query touching 10 big tables. The optimizer chooses to start with a bad index access on a table: both index columns are defined as nullable, and my search criteria needs to have both columns having the NULL value.

The pitty is, that 2/3 of the rows in the table posses this combination.

I have no chance to create propper statistic values for these index columns, since I have no access to our DBAs.

The alternative I come to think of is to make these predicates "not indexable". Forcing this attribute for normal comparing operations (=, >=, etc.) for numeric, character or date/time formats is no problem.

The question is: How can I achieve the status "not indexable" for a predicate "column IS NULL"?

kind regards
Christian

[kolusu]

Czerfas,

There are many ways to make a predicate nonindexable. The recommended way is to make the add 0 to a predicate that evaluates to a numeric value or concatenate a predicate that evaluates to a character value with an empty string.