Does MongoDB automatically create collection?
MongoDB creates collections automatically when you insert some documents. For example: Insert a document named seomount into a collection named SSSIT. The operation will create the collection if the collection does not currently exist. If you want to see the inserted document, use the find() command.
What is DB collection drop ()?
collection. drop() method is used to drop a collection from a database. It completely removes a collection from the database and does not leave any indexes associated with the dropped collections. The db. This method removes all the indexes associated with the dropped collection.
Which method is used to drop collection in MongoDB?
collection.drop()
drop() is used to drop a collection from the database.
How does db.collection.drop ( ) work in MongoDB?
The db.collection.drop () method and drop command create an invalidate Event for any Change Streams opened on dropped collection. Starting in MongoDB 4.4, the db.collection.drop () method and drop command abort any in-progress index builds on the target collection before dropping the collection.
When to omit write concern in MongoDB drop?
Omit to use the default write concern. When issued on a sharded cluster, mongos converts the write concern of the drop command and its helper db.collection.drop () to “majority”. New in version 4.0. true when successfully drops a collection.
How to flush cached routing table in MongoDB?
For a sharded cluster, if you use db.collection.drop () and then create a new collection with the same name, you must either: Flush the cached routing table on every mongos using flushRouterConfig. Use db.collection.remove () to remove the existing documents and reuse the collection.
How does the abort OpLog work in MongoDB?
MongoDB attempts to abort the in-progress builds for the specified indexes on the primary and if successful creates an associated abort oplog entry. Secondary members with replicated in-progress builds wait for a commit or abort oplog entry from the primary before either committing or aborting the index build.