Oracle Database Discussions

Please I'm having some issue configurting the LOG_CHECKPOINT_INTERVAL paraneter.
My redo log file size is 300M, and I need to initialize this parameter so, the checkpoint could arise only after a switch log file.
This is the value that I put:
Alter system set LOG_CHECKPOINT_INTERVAL =620 000 scope=both;

300M=307200K=314572800 bytes.
the OS block size is 512 bytes.
so 62 0000=314572800/512,because the LOG_CHECKPOINT_INTERVAL is given by number of redo log blocks, and the redolog blocks is taken from the OS.

But I'm still having a log switch(checkpoint incomplete), It sounds like this doesn't have effect on the database, I'm thinking to increase the redolog file from 300 to 1G and add one more group, as well as adjusting the above parameter, does someone have another idea?

Thanks for your help