In MongoDB, the dropIndexes() method allows you to drop one or more indexes from a collection.
To drop a single index, pass the name of the index or its definition/specification document. If it’s a text index, you can only specify the index name.
To drop multiple indexes, pass the index names in an array.
To drop all indexes (except for the _id index), don’t pass any arguments.
There are several ways to drop an index in MongoDB, one of which is to use the dropIndex() method.
It’s pretty simple to use – just pass the name of the index or its definition/specification document. If it’s a text index, you can only specify the index name.
Continue readingIn MongoDB, you can use the getIndexes() method to get a list of indexes on a collection.
You can also loop through each collection in a database to return all indexes in the database.
Continue readingIn MongoDB, the db.collection.unhideIndex() method unhides a hidden index.
A hidden index is one that’s hidden from the query planner. When you unhide an index, it is no longer hidden from the query planner, and it’s immediately available for use.
Continue readingMongoDB introduced the db.collection.hideIndex() method in MongoDB 4.4.
This method hides an existing index from the query planner. This allows you to evaluate the potential impact of dropping an index without actually dropping the index.
If hiding it has a negative impact, you can use db.collection.unhideIndex() to unhide the index. This saves you from having to drop the index, then recreate it.
In MongoDB, you can create an index on a collection using the createIndex() method, the createIndexes() method, or the createIndexes administration command.
There are several ways to create an index in MongoDB, and from MongoDB 4.2, we can create wildcard indexes.
A wildcard index can be thought of as a kind of filter that automatically matches any field, sub-document or array in a collection and then indexes those matches.
Continue readingIn this article I outline two ways to return a list of indexes in an SQLite database.
The first (and most obvious) method is to use the .indexes dot command. The second method is to query the sql_master table.