Re: Faster key lookup

[Stuart Rowe <rowestu@xxxxxxxxx>]

Justin,

And (COLUMN4 = :local4 or :local4 = '');

That's just a way to express "if local4 is not empty, test it".  Allows
selection on COLUMN4 to be optional based on the zero length value of
local4.







On Thu, Jun 28, 2018 at 7:53 AM Justin Taylor <JUSTIN@xxxxxxxxxxxxx> wrote:

> I've never heard of user indexes, but it sounds like what I'm looking
> for.  I found the API's for reading and writing.  There was a performance
> warning about auto-flushing to disk, but I don't imagine that would be a
> problem since I’d only be writing once a day.
>
> My final condition, "And (COLUMN4 = :local4 or :local4 = '');" would be an
> issue.  I'm not sure what the point of that was, so I'm going to have to
> research it.
>
>
>
> -----Original Message-----
> From: Mark S Waterbury [mailto:mark.s.waterbury@xxxxxxxxxxxxx]
> Sent: Wednesday, June 27, 2018 7:52 PM
> To: rpg400-l@xxxxxxxxxxxx
> Subject: Re: Faster key lookup
>
> Justin,
>
> Create a User Index, and read the file, and use the MI built-in
> instruction INSINXEN to insert index entries into that *USRIDX object, and
> then your look-up procedure can just use the MI built-in FNDINXEN
> instruction.
>
> This should be very fast.  You can even "pin" the *USRIDX object in a
> memory pool, by using the SETACCST MI instruction, or using the SETOBJACC
> command.
>
> Then, once a day, or as needed, just refresh the contents -- probably
> simplest to just delete and recreate the whole *USRIDX object.
>
> Hope that helps,
>
> Mark S. Waterbury
>
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