RE: How does ebay do it? -- MIDRANGE-L

Title: RE: How does ebay do it?

I would appreciate any code you would like to share... And thanks for the list of pitfalls and ideas...

Hope you have a nice weekend...
tim

-----Original Message-----
From:   James W. Kilgore [SMTP:eMail@James-W-Kilgore.com]
Sent:   Friday, March 30, 2001 12:08 PM
To:     MIDRANGE-L@midrange.com
Subject:        Re: How does ebay do it?

Tim,

If you want a working example I'll post it at Netshare400 this weekend.

The program comes in two flavors: 1) a first time batch run to build the
index 2) a maintenance program (called via your trigger) to keep the
index up to date.

If not, here's some of the issues and design considerations we had to
address:

1) mixed case text

What we did was define a file translation table which automatically
translated the characters to upper case for output to the index. IMHO,
letting the system do this is at the buffer level is faster than using
XLATE.

2) word delimiter

In the same translation table above, we translate special characters
into blanks, we use a blank as a word delimiter.

3) How big to make the keyword

We decided to use only the first 8 characters of a word. Why 8? This
was originally written for the S/34 and 8 + key = optimized record
length. Doesn't really matter any more, but it works.

4) Reducing the size of the index by omitting common words like: the,
and, Inc, of

This was included because of the programs roots and disk space was at a
premium. Doesn't really matter much any more. Depending upon your
database it may still make sense.

5) In using the file translation table, beware of packed fields

Create a logical that only includes the fields to be indexed and process
this file.

HTH

> "Hatzenbeler, Tim" wrote:
>
<<snip>>
>
> but in the mean time, i'll work on my index program... and as we
> upgrade our system, i'll replace it with newer database features.
>
+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---