Why tuning and what is Granule unit
As a DBA you,
are also responsible for detecting
performance problems of your organizationís
database. You need to know how to start
investigating a performance problem and then
solve it. Your jobís responsibilities
dictate that you should at least be informed
of the following basic fundamental subjects:
this exercise you will learn about the
GRANULE unit, and how to perform performance
clients complain about application
performance, you look at the problem with
the following sequence.
1- SQL Statement tuning,
2- Optimizing sorting Operations,
3- Memory Allocation.
a- Operating System Memory size,
b- Oracle allocated Memory size (SGA-System
4- I/O contentions,
5- Latches & Locks,
6- Network Load.
the SGA components are allocated and
de-allocated in units of contiguous memory
called Granule. So it is very important that
the amount of allocated memory must be a
product of the Granule size and an integer.
If the SGA is less than 128MB, then a
granule is 4MB. If the SGA is larger than
128MB, then a granule is 16MB.
The minimum number of granules allocated at
startup is: 1 for the buffer cache, 1 for
the shared pool, and 1 for the fixed SGA,
which includes redo buffers.
Q: How do you
perform tuning on your database?
Q: What is a
Q: How does a
granule unit work in an increasing or
decreasing the database memory?
Q: When a
client complain about his/her application
performance, what are the list of steps you
Q: If the size
of your SGA is greater than 128M, what is
the size of your database granule unit?
Q: If the size
of your SGA is less than 128M, what is the
size of your database granule unit?
Q: What is the
minimum number of granules allocated to the
buffer cache, and the shared pool?