Question:Is there any rule/formula evaluating sysstat: Enqueues Statistics

[CMT]

Hi,

v$Sysstat statistics are helpful in giving system wide "Health Check"
indicator how the database is performing.

Question: Is there any rule / formula for
evaluating and grading (Good/poor/error)
the v$sysstat values relating to CLASS - Enqueues statistics

which are:
25 - enqueue requests
22 - enqueue timeouts
23 - enqueue waits
24 - enqueue deadlocks

For example -

1) if 22 + 23 + 24 is over zero then ...

or

2) if 22 + 23 + 24 is a certain percentage of 25


For example for Class Buffer -
there is a system Buffer Cache Hit Ratio formula:
1-('physical reads'/('db block gets')+('consistent gets') )
where for example one can grade the results:
Between 90 - 100 OK
Between 80 - 90 Warning
Between 0 - 80 Error

Is there a rule/formula for Enqueue like my example for Buffer
(I was not able to find in Metalink) ?

Thanks in advance,
CMT

[pando]

Originally posted by CMT

For example for Class Buffer -
there is a system Buffer Cache Hit Ratio formula:
1-('physical reads'/('db block gets')+('consistent gets') )
where for example one can grade the results:
Between 90 - 100 OK
Between 80 - 90 Warning
Between 0 - 80 Error

that is pretty much useless nowdays

[CMT]

To pando -

You wrote: "that is pretty much useless nowdays"

Why ; explain?

Even statspack report calculates and reports it
as part of the spreport?

BTW - You did not address my question that referred to enqueues

CMT

[marist89]

Originally posted by CMT
To pando -

You wrote: "that is pretty much useless nowdays"

Why ; explain?

Even statspack report calculates and reports it
as part of the spreport?

Search this site and the web why this is useless.

You did not address my question that referred to enqueues

Ratios are approximations. In some situations they may fit, some they may not. Show me a ratio, and I'll show you how to both prove and disprove your theory. Here you will get invalid information if you overuse 'FOR UPDATE'.

[CMT]

marist89,

How do you monitor your databases ?
Do you use statspack ?

BTW -
Which site were you referring to: "Search this site"
the url is missing

[Thomasps]

Originally posted by CMT
marist89,

BTW -
Which site were you referring to: "Search this site"
the url is missing

http://www.google.com

[marist89]

Originally posted by CMT
marist89,

How do you monitor your databases ?

I use a combination of things; custom database scripts, custom OS scripts, statspack, etc.

Do you use statspack ?

Yes. I use statspack to compare my workload over time. I also use it to diagnose instance wide problems where appropriate.

Which site were you referring to: "Search this site"
the url is missing

http://www.dbasupport.com/forums/search.php

[tamilselvan]

=========
25 - enqueue requests
22 - enqueue timeouts
23 - enqueue waits
24 - enqueue deadlocks

==========
If you think enqueue latch contention is high in your system, then you need to look into application code /design for tuning.

There is no fixed formula or fixed solution to tune latch contention.

Tamil