So, playing devil's advocate here:
I have no idea if our products have ever built a view or an index over system tables, but...... If my software relies on info from those tables, and my queries performed poorly due to lack of indexing, what else would you have the vendor do? Petition IBM to build the indexes? And then they MIGHT show up 6 month from now in PTFs.
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxx> On Behalf Of David Gibbs
Sent: Thursday, November 15, 2018 10:34 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: Re: Do third party products add access paths to system tables often?
On 11/15/2018 10:28 AM, Mark Waterbury wrote:
It depends in part on what you mean by "a system table." Do you mean
a 3rd party product added an SQL index or view (or even a traditional
DDS-based LF) over an IBM-supplied table that is part of, or shipped
with, the OS?
I'm talking about an access path built over a file in QSYS or QSYS2.
So, what's the real issue here? Can you explain what kind of
problem(s) this incident (support case) caused?
We had a program that was reading a system table in arrival sequence (no sort order specified on the OPNQRYF) and were getting the data in unexpected order.
After running the program in debug, we saw that an unexpected access path was being selected, so we were getting the data in a specific order.
Granted, our program should have specified the sequence instead of relying on it being in the correct order.
None the less, I'm wondering if it's common place for 3rd party products (or even end users) to create access paths over system tables.
We were able to resolve the issue, but it was surprising that it was encountered at all.
david
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