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

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

Quote:

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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

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

Quote:

---

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.

Quote:

---

You did not address my question that referred to enqueues

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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'.

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

Quote:

---

Originally posted by CMT
marist89,

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

---

http://www.google.com :D

Quote:

---

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.

Quote:

---

Do you use statspack ?

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

Quote:

---

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

---

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

=========
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