× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



James, read up "SQL Union Tip" article on page 6 of this newsletter:

http://www.centerfieldtechnology.com/publications/archive/SeptOct08.pdf

If you can use UNION ALL without functional implications, it might help
reduce "query running" time.

If the only query is by part number, you can build an index over part number
on all 3 fields (3 separate indexes). You can make them binary radix index
(default) or an EVI (Encoded Vector Index).
DB2 for i can perform bitmap merging for both type of indexes.

Command to use to build indexes is CREATE INDEX. You can use interactive
SQL (STRSQL command) to build them, or iNav's Run SQL Scripts (click on
Start->Run->cwbundbs->OK [provided you have IBM Client Access installed on
your PC]).

Hth, Elvis

Celebrating 11-Years of SQL Performance Excellence on IBM i, i5/OS and
OS/400
www.centerfieldtechnology.com


-----Original Message-----
Subject: Re: Searching across three files

Thanks, "sjl", Roger, and Vern; that did the trick.

Using one of the files of the QuestView demonstration suite (namely
VIEWPRT) as a guinea-pig, I split it into three files (VIEWPRT1,
VIEWPRT2, and VIEWPRT3), removed a few records, and added a few, so that
I ended up with three files with a slight overlap between them. I then did:

CREATE VIEW VIEWPRTC AS SELECT * FROM MERCURY.VIEWPRT1 UNION SELECT
* FROM MERCURY.VIEWPRT2 UNION SELECT * FROM MERCURY.VIEWPRT3

which created the desired dynamically consolidated logical. Opening it
from QuestView caused a slight delay with "query running" messages, but
quickly coughed up the consolidated part-catalog files. The acid test,
tying it into the look-up specs and calling the lookup program in
"command-line test" mode also produced the desired results.

One thing: how would I index this, for better performance if the user is
doing the look-up by part-number? Unfortunately, while I vaguely
remember SQL indexing from a class I took in Rochester, neither my
memory nor my copy of "SQL for Dummies" have a whole lot to say on the
subject.


As an Amazon Associate we earn from qualifying purchases.

This thread ...

Follow-Ups:
Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.