Calculate number of max cursors open

[psoares]

1 - Anyone can tell me the way that i can calculate the maximium number of cursors open that i should define in ora.ini , just by the usual work of an aplication and the analysis of the database or any other way i can mesure?


2 - Is there any way to calculate the number of rolback segments i should create in a database and it´s storage?



Thanks you for your help

Paulo

[hrishy]

Hello


1)Anyone can tell me the way that i can calculate the maximium number of cursors open that i should define in ora.ini , just by the usual work of an aplication and the analysis of the database or any other way i can mesure?

This is very difficult to measure usually you will have to set it with experience never accept the default at my site it is 200 i mean the current site at my last site it was 500 (developers did not have the habit of closing the cursors there i guess :-D

2)Is there any way to calculate the number of rolback segments i should create in a database and it´s storage?

it depends Oracle instructors whom i have met say you should have 20 rollback segments .one rule of thumb is

number of transactions / transactions per roll back segment

usually i assign 4 users per rollback segment

by tht rule sppose i have 50 transactions and with 4 transactions per rollback segment

i will have roughly 12.5 rollback segments but according to the rule i should make this number an exact multiple of 4 so i use 16 .

among other things i have script to tell me wheather the rollback segments that i have created are enough.

Hope this helps
Regards
Hrishy

[dknight]

I agree with hrishy on point (1).

You don't want to set the parameter too low, however, the number of open cursors should not grow steadily.

Good luck.

[julian]

usually i assign 4 users per rollback segment

Oracle recommends that in Oracle 8i. For older versions of Oracle it is a bit more. I assume that by '4 users' you mean 4 concurrent users :-)