Unidata 7.3.3 on RedHat: I have a table with numerous indicies built:
File.................. H08.CR.COURSE.EVALS
Alternate key length.. 20
Node/Block size....... 4K
OV blocks............. 1 (0 in use, 0 overflowed)
Indices............... 6 (6 D-type)
Index updates......... Enabled, No updates pending
Index-Name...... F-type K-type Built Empties Dups In-DICT S/M
F-no/VF-expr....
XCCE.STUDENT.ID D Num Yes Yes Yes Yes S 8
XCCE.STATUS D Txt Yes No Yes Yes S 17
XCCE.COURSE.NAME D Txt Yes No Yes Yes S 14
XCCE.TERM D Txt Yes No Yes Yes S 12
XCCE.TYPE D Txt Yes No Yes Yes S 22
XCCE.SUBJECT D Txt Yes No Yes Yes S 23
Since these are data fields (nothing computed on-the-fly) and indexed,
queries should be fast. The table has approximately 737,000 records.
This query runs in under 1 second:
SELECT H08.CR.COURSE.EVALS WITH XCCE.TERM EQ '2013F'
However this query takes 10+ seconds (or longer) - even with two indexed
fields:
SELECT H08.CR.COURSE.EVALS WITH XCCE.TERM EQ '2013F' AND XCCE.TYPE EQ
'FINCRSE'
I'm at a loss to explain the second, any insight appreciated.
--
Jeffrey Butera, PhD
Associate Director for Application and Web Services
Information Technology
Hampshire College
413-559-5556
_______________________________________________
U2-Users mailing list
U2-Users@listserver.u2ug.org
http://listserver.u2ug.org/mailman/listinfo/u2-users
