Determine the appropriate number of standby redo log file groups.

# Thread: Determine the appropriate number of standby redo log file groups.

1. Member
Join Date
Mar 2006
Posts
176

## Determine the appropriate number of standby redo log file groups.

I read the Oracle docs and below is what Oracle recommended:

(maximum number of logfiles for each thread + 1) * maximum number of threads

Below is what I had on my primary:

select a.group#,b.thread# from v\$logfile a, v\$log b
where a.group#=b.group#
order by 1

1 1
1 1
2 1
2 1
3 2
3 2
4 2
4 2
5 3
5 3
6 3
6 3
7 4
7 4
8 4
8 4
9 5
9 5
10 5
10 5

Based from the formula and what I had on my primary, is it right to say I would need the total of 24 SRL?

(5+1)*4 --five log files for each thread plus one and multiply 4?

thanks

2. ## Yes

Originally Posted by matthew00
I read the Oracle docs and below is what Oracle recommended:

(maximum number of logfiles for each thread + 1) * maximum number of threads

Below is what I had on my primary:

select a.group#,b.thread# from v\$logfile a, v\$log b
where a.group#=b.group#
order by 1

1 1
1 1
2 1
2 1
3 2
3 2
4 2
4 2
5 3
5 3
6 3
6 3
7 4
7 4
8 4
8 4
9 5
9 5
10 5
10 5

Based from the formula and what I had on my primary, is it right to say I would need the total of 24 SRL?

(5+1)*4 --five log files for each thread plus one and multiply 4?

thanks
Correct.

3. Member
Join Date
Mar 2006
Posts
176
actually, it should be 20 instead of 24. b/c four log files/per thread plus one and multiply by four.

4. Originally Posted by matthew00
actually, it should be 20 instead of 24. b/c four log files/per thread plus one and multiply by four.
Seems your first post is confusing because of the duplicate entries in your query.

For example, if you have 5 threads of 2 logs each (or 10 logs), you need an equal number of standby threads (or 10 logs) plus one additional thread ( 2 logs)

10 regular + 12 standby.

Ooops, that makes 22...
Last edited by LKBrwn_DBA; 10-25-2010 at 03:17 PM.

5. Junior Member
Join Date
Apr 2008
Location
Bangalore
Posts
96
can any one let me know where this is documented...i want to read more..

6. Originally Posted by Mohith123
can any one let me know where this is documented...i want to read more..
Nothing beats the vendor's documentation, isn't it?

OracleŽ Data Guard Concepts and Administration
10g Release 2 (10.2)
Part Number B14239-05