Please help - its realy urgent

[orauxpro]

Hello everybody.


1. I am new to the DBA, Any tips for me Regarding Tuning Rollback Segments and Tuning I/O and CPU Resources.I am working on HP-UX 11, WITH ORACLE 8
2. I ALSO NEED some help on how many redo log files can i have, and where can i set the number of the redo logfiles, and how big the redo logfiles can be.

3. my database is very slow how can i make it faster, what area should i look for.



Thanks,

 

[Swany]

2. I ALSO NEED some help on how many redo log files can i have, and where can i set the number of the redo logfiles, and how big the redo logfiles can be.
The redo settings are found in the init.ora file
Oracle usually recommends three redo log files. They should
be placed on three seperate disks. The archive logs (assuming you are in archive logging mode) should be written to a forth disk to prevent contention. I've used solid state drives for REDO logs with much success and had significant performance increases doing so. This may be something that you want to look into.

3. my database is very slow how can i make it faster, what area should i look for.

It depends on what the database is slow doing. First you need to check the size of the SGA versus the amount of memory that is free on the system. If vhand or swapper are consuming a lot of CPU time, then you are swapping and need to add more memory to the system.

Check the kernel parameters in SAM. By default HPUX allows the file system cache to consume up to 50% of available ram. You should decrease that to 5% if the system is being used mainly as a database server. The SGA handles the cacheing of oracle data, there is no need to use the OS disk cache.

Check and see what disks are getting the most IO with "sar". See if there is any latch contention and what processes are waiting on disk access and CPU access. Once again, if CPU utilization seems high and IO seems high then check to make sure you aren't swapping.

If your system seems to be running excessively slow, I would recommend you have an experienced oracle dba and hpux system admin come in and tune things for you. Inexperienced tuning can lead to more performance problems than leaving things just as they are.

 

[orauxpro]

thank you very much guys u been greate help, i am experinced unix and oracle.