Re: native i/o and RCAC - performance

[x y <xy6581@xxxxxxxxx>]

Lots of reasons performance could be different, not the least of which is
the possibility that the file's been pulled off disk hard disk and is
sitting somewhere in single-level storage. I'd run this test at least 10
times in succession, alternating with/without RCAC, to tamp down system
workload and the other unseen factors that play havoc with performance
measurement.  My development partition has 245 jobs running--a handful of
QINTER's, one user daemon, and a handful of

It seems that this feature is extremely useful in some very specific use
cases, primarily to protect financial and employee-confidential data, but
not the most effective for dealing with performance issues. Another
approach is to create a covered index/access path, where all the
fields/columns needed for a given query are included in the "logical".

On Thu, May 13, 2021 at 5:57 AM Jay Vaughn <jeffersonvaughn@xxxxxxxxx>
wrote:

> Can anyone explain or even theorize when applying RCAC to a file, how it
> boosts the read performance of the file under native i/o?
>
> Example:
>
> file containing 5M rows...
> simple RPG pgm in for loop with reads...
>
> without RCAC applied
> elapsed time - 23s
> processing time - 1.544
>
> with RCAC applied (alter table theTable activate column access control)
> elapsed time - 4s
> processing time - 1.413
>
> drastic change in elapsed time - small change in processing time.
>
> There is also a smaller gain when using SQL but not as much as native i/o.
>
> tia
>
> Jay
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