RE: Should I replace all CHAIN, SETLL, and READs to SQL

["Briggs, Trevor (TBriggs2)" <TBriggs2@xxxxxxxxxxx>]

Nathan,

Did you benchmark SELECT COUNT(*) FROM XXXX WHERE..... ? 

I've found this much faster than SELECTing other ways for just checking a record's existence.

Trevor Briggs
Analyst/Programmer
Lincare, Inc.
(727) 431-1246
TBriggs2@xxxxxxxxxxx
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Nathan Andelin
Sent: Friday, November 02, 2012 1:18 PM
To: RPG programming on the IBM i / System i
Subject: Re: Should I replace all CHAIN, SETLL, and READs to SQL

> How this would affect performance

There's a Linkedin discussion which kind of addresses this. I posted a couple benchmarks testing SETLL vs. sql select 1 into :found ... to check for existence of a record. SETLL was 4.5 times more efficient in one case, and 6.5 times more efficient in the other.

http://tinyurl.com/d62ptmc


We use both RLA and SQL extensively. SETLL and CHAIN perform significantly better than SQL SELECT ... INTO ...  SQL performs better for most queries that generate significantly sized or summarized result sets, mass updates and mass deletes.

-Nathan