Re: READE vs. READPE performance

I have used both, but not for multiple simultaneous reads.  For the
performance issue, it would be best to use READ on the descending-key file,
or READP on the ascending key file, and crank up the block size using OVRDBF
FILE(LOGICAL1) SEQONLY(*YES XXXX), where XXXX is the max number of records
that will fit in 128k.

Basically, SetLL and then READ or READP in a loop, and check key values each
iteration through.

On 12/9/05, Ben_Pforsich@xxxxxxxxxxxx <Ben_Pforsich@xxxxxxxxxxxx> wrote:
>
>
> Generally speaking, has anyone tried or know for a fact which of the
> following scenarios result in better performance (faster I/O?)?...
> 1.  READE on logical with a descending key  (ex:  READE (Company : Route :
> Date) LOGICAL1 where Date is keyed descending)
> 2.  READPE on logical with an ascending key  (ex: READPE (Company : Route
> :
> Date) LOGICAL2 where Date is keyed ascending).
>
> I want to read records in a history transaction file keyed with a date
> field starting with the most recent and going backward.  I'm trying to
> decide whether I should build a new logical over a fairly large physical,
> or use an existing logical and use READPE instead of READE.  I will be
> likely reading potentially 10,000 to 50,000 records in one pass and
> performance is an issue.
>
> Let me know if you need more information, but I was hoping for a quick and
> dirty response.
>
> Thanks!
>
> Ben Pforsich
> Programmer Analyst
> Bob Evans Farms, Inc.
> I/S Department
> Columbus, Ohio
> Ben_Pforsich@xxxxxxxxxxxx
>
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