My suggestion would have changed the plan to

PLAN JOIN (DET INDEX (RDB$FOREIGN2),CAB
INDEX(RDB$PRIMARY31))

something which will be faster than

PLAN JOIN (DET INDEX (RDB$FOREIGN2),CAB
INDEX(RDB$PRIMARY31,FCAJA_CAB_IDX_FECHA))

Only your testing will reveal whether it also is quicker than (or equally
quick to)

PLAN JOIN (CAB INDEX (FCAJA_CAB_IDX_FECHA),DET
INDEX(RDB$PRIMARY33,RDB$FOREINGN2))

or not. If not, then the only way I can think of to force the plan you
want, is to specify it explicitly. By the way,

PLAN JOIN (CAB INDEX (FCAJA_CAB_IDX_FECHA),DET
INDEX(RDB$PRIMARY33))

will be a better plan than

PLAN JOIN (CAB INDEX (FCAJA_CAB_IDX_FECHA),DET
INDEX(RDB$PRIMARY33,RDB$FOREINGN2))

HTH,
Set

At 13:00 17.06.2003 -0400, you wrote:

>PLAN JOIN (CAB INDEX (FCAJA_CAB_IDX_FECHA),DET
>INDEX(RDB$PRIMARY33,RDB$FOREINGN2))
>
>and not as at the moment it Works:
>
>PLAN JOIN (DET INDEX (RDB$FOREIGN2),CAB
>INDEX(RDB$PRIMARY31,FCAJA_CAB_IDX_FECHA))
>
>You have some solution?