How do the MongoDB journal file and oplog differ?

Question

I have recently started on MongodDb and I\'m trying to explore on replica sets and crash recovery.

I have read it like journal file are write a head redo log file. oplog

Answer 1

There must be a relationship between journal and oplog. when w=1 u commit to primary jouranl and also created an oplog entry for replset collection. I think at least in primary of a replSet - they both contain same update/delete/insert just in different format.