Any caluculation ro formula to size redo log

[marist89]

Originally posted by chandoos
Hi
I would like to know is there any formula or caluclation in sizing the redo log.

(db_block_size * some_number * #_members ) / #_redo_logs

[gandolf989]

Originally posted by chandoos
Hi
I would like to know is there any formula or caluclation in sizing the redo log. apart from the general funda and talk.

The amount of redo you generate depends on the total tranaction per minute and the average size of your tranactions. The other factors that go into sizing redo logs are how much data can you afford to lose if you lose your database and all of your online redor logs.

If you size you redo logs to 100 megs each, have them duplexed, and get a log switch every 10 minutes. You have them sized correctly as long as you database performance is good, and your are not getting errors and or warnings when the log switch happens.

If you are getting errors like check point not complete, or if you are doing log switches too often or almost never you will need to readjust the size of your redo logs or add additional log groups.

There is no formula for calucalting the size of your redo logs!

[gandolf989]

Originally posted by marist89
(db_block_size * some_number * #_members ) / #_redo_logs

I can't tell if you are being serious or if you are joking.

[marist89]

Originally posted by gandolf989
I can't tell if you are being serious or if you are joking.

better?

[raghud]

Jeff Hunter ,, Serious ?? .He is Like "J W BUSH" President of Amer_Jamica.

[wasif003]

Sizing redo logs doesn?t rely on a strict formula, but rather on workload analysis and log switch frequency.

A commonly accepted approach is to size redo logs so that log switches occur every 15?30 minutes during peak usage. This helps balance performance and recovery time.

You can estimate it like this:

Determine redo generation rate
Example: 6 GB per hour ≈ 100 MB per minute
Choose a target switch interval
Example: 20 minutes
Calculate redo log size
100 MB ? 20 = ~2 GB per redo log file

After that, monitor system behavior and adjust if needed.

⚙️ Best Practices:
Maintain 3?4 redo log groups
Keep sizes consistent
Avoid too frequent switches or excessively large logs
🔗 Additional Insight:

Interestingly, the same principle of using historical data and real-time patterns applies in other areas too. For example, tools like
snow day prediction tool
use past trends and current conditions to improve prediction accuracy?similar to how database tuning relies on workload patterns.