In this post, I would go through a case where I identified a solution to a SQL statement whose performance was perceived as good/normal. My solution made an over 99.99% improvement on time needed to execute the SQL via table reorganization. Index rebuild/table reorg is not always making noticeable performance improvement for related SQL most…
Galleries
Case Study – Use ST04 SQL Stats history in Performance analysis
This post covers how I used SQL historical stats from SAP ST04 in analyzing a true performance incident related to SAP system cloud migration. I used SQL stats from “good” and “bad” periods and compare the stats and found where the problem was. This led to resolution of performance issue. You can refer to my…
SAP ST04 performance feature – DBA History
After I posted my blog on how to run SAP ST04, SAP introduced a new feature into ST04 – DBA history which can show history of SQL stats which is only available via separate SQL script before. This is a very helpful feature in SQL performance analysis. In this post, I would talk about the…
How to deal with SAP program performance issue due to suboptimal execution plan
It is not often but can happen that a SAP transaction/process is suddenly running abnormal longer due to extracting data from database without known application changes such as volume, setting and logic. This type of performance issue is normally due to fact that database has switched to a suboptimal plan instead from a good execution…
Understanding SQL Execution plan in SAP environment
In analyzing a SAP program which spends most of run time in reading data from database, SQL execution plan is often a focus. This post would share my knowledges on SQL Execution plan in a SAP/Oracle environment. It covers following: Oracle SQL execution plan introduction, How to read an oracle SQL execution plan in SAP…
Many SAP work processes were left in “on hold” status with RFC info
I was contacted on one production issue – Almost all SAP background work processes were in “on-hold” status with RFC info in SAP SM50 work process monitor transaction and seemed like not moving. I was asked why? Please continue reading to understand the reason which I identified through analysis via transaction SM50, STAD, RZ12. This…
Explanation of SAP STAD Single Statistical Records/data
SAP STAD is one of my frequent used SAP transactions in performance analysis. STAD can show you where the time is spent over a list of technical components involved in a job/program execution, so it is often 1st step I would take to review performance of a program/transaction which finished recently. Following my previous post…
Mass VS Individual deletion – Does it matter to SAP program performance?
My previous post – “SAP ST12 Trace – SQL performance analysis” mentions that we can use mass/array database operation to replace many individual execution of the same SQL to improve database access performance. This blog will go through a true business case where a code has been changed to use array/mass SQL deletion to replace…