[MVS DB29] Predicate "and 1=1" has filter factor 0.04

Hubertus Beucke

[MVS DB29] Predicate "and 1=1" has filter factor 0.04
Hi ALL,

the following SQL was examined with OSC:

select *
from sysibm.systables
where createdby = 'SYSIBM'
and 1=1;

It provides a filter factor of 0.0012 for the stage 1 predicate "createdby = 'SYSIBM'". This is plausible. Not so the filter factor 0.04 for the stage 2 predicate "1=1". This filter factor is 1, because the predicate is always true.

Regards
Hubertus

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