Archive Logs in every 15 minutes(Oracle 11g 64 bit EE on Linux RHEL 4

Question

In our production database we have very few transactions may be of few MB's in whole day but it is generating archive logs constantly in every 15 minutes(may be sometime in 14 minutes also) of file size 50 MB each and this way consume 4 GB of space in a day for archive log which is way above than expected.
I have checked archive_lag_target and value of this is 0.
Any clue why it is creating 50 MB archive log file after every 14-15 minutes?

Answer 1

It's easy enough to reduce redo log file size without downtime; just add new smaller redo log files, switch logfile a couple of times and drop the old redo log files.
However, if the redo logs are filling up before they switch, then this will probably only make matters worse.
If the redo logs are switching before they are full then maybe you also need to consider log_checkpoint_interval and log_checkpoint_timeout settings.
If the redo logs are filling up before they switch then use the techniques suggested by a couple of the other posters to track down the guilty SQL.