Is there a limit to # of indexed fields you can use in1 report? (AREV Specific)
At 01 AUG 1998 01:41:19PM Ed Johnson - mredwci@cboss.com wrote:
Hello again,
I'm Using an AREV 3.12 application and the NLM:
In an effort to speed up the response time to reports that impact a 10,000 to 30,000 record database, I've built indexes on 8 or 9 fields; some are multi-valued. The SELECT impacts 4 fields in most cases. Three of the 4 fields had Btree indexes running, so I decided to build an index on the fourth. After building and attaching (logged out - then back in) I got "Zero rows found." After removing the index, the correct results were obtained.
Is there such a thing as "too many indexes", and if so, what are the rules?
Any help will be appreciated.
Ed Johnson
At 03 AUG 1998 04:55PM K Gilfilen wrote:
Ed,
AREV should handle four indexed fields well enough.
Have you established that the logic of your query is correct? Can you run the fourth (failing) clause separately and get a good result? You can try to narrow down the problem by executing each clause separately and doing a "savelist listname". View each list from the lists file ("edit lists listname") to visually see what record ids you get back. Then do a "getlist same listname" to bring the select list into active memory, and run another select list against that one.
If you get everything up to but not including that last query into a list, then you can repeatedly monkey around with that query to determine if it is doing what you want it to do.