Experiments from the Field..Based on True Stories

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Meaning of True knowledge in Sanskrit:

Neither can a thief steal it, nor can a powerful politician take it,
Neither can it be divided amongst brothers, nor is too heavy to carry.
The more it is expended or shared, the more it increases.
Knowledge is prime amongst all wealths.

Education gives Humility; Humility gives Character; from character one gets wealth; from wealth one gets righteous life & righteousness in life leads to happiness.

Let the fruits of our efforts be offered as sacrifice for nurturing a Knowledgeble & Transparent Intellect.

Some observations relevant to any application on 32bit platform architecture using RHAS3 OS using Java1.4 and J2SE 1.5 in various variants of Linux Redhat kernels.

Read the case study here...

Most people believe that one cannot go beyond 1.2g-1.7g or so as a maximum heapsize for Java servlet based applications deployed with 9iAS/10gAS.

There is more to it than meets the eye. Read on more...

                                       

This case study deals with Oracle configurator product (shortcode CZ) of 11i Oracle Applications and how to make it more stable and scalable by leveraging the LargePages option provided in J2SE1.5. This paper is in continuation to earlier article Common Incorrect beliefs about process address limits on 32bit platforms

It is assumed that the maintenance release of 11i Oracle Applications is 11.5.10 as per certification specified in Note 304099.1 - Using J2SE Version 5.0 with Oracle E-Business Suite 11i. To find the latest version of Java certified with the E-Business Suite application tier, please see OracleMetaLink Note 300482.1, titled "Overview of Using Java with Oracle E-Business Suite Release 11i".

This study assumes RHAS3 as the running platform OS.

The advantage of using largepages is that the heap memory will be locked and is not eligible for paging out on swap. The access of objects in heap in real memory is obviously faster.

Hence, using Largepages option is a good option  for achieving performance goals, especially when the caching demands in the servlet are considerable and there is a section of RAM on the machine running servlet, which is not being put to any use.

Read the entire Story here..

While it may not be ideal, at times, it may be required to supplement
or coach the CBO to achieve acceptable levels of application
performance.

They say: Tune the application first.
And then, many a times, the CBO behaviour is not predictable or
favourable, inspite of its best intentions or internal hueristic rules
or availability of latest statistics with good sampling percent.

This
is one such example in which Hints had to be used as one of
the last options to improve the performance of a concurrent program.

Read the entire case study here...

Its always rewarding to talk about lesser known performance tuning scenarios, which are not all that well appreciated in the DBA or developer world. Ask anyone as to what performance tuning has one worked upon and quite likely, you may hear - Ah well, I made sure the stats gathered were the latest, the right index was being used or I used a hint to use the right index. Typical Answer.

How often do we look at other aspects like the frequencey of commits?

Neither is it good to do commits less frequently, nor is it good to over-commit. Moderation is the key for a happy medium and at times, it can have bearings on performance problems as well.

Read the complete discussion here...