The following example shows how add index to collection. So even if the search query is based on the EmployeeCode “AA”, that document would be returned.Ĭreating an Index in MongoDB is done by using the “ createIndex” method. So when a query search is made, these indexes will be used to quickly and efficiently find the required documents in the collection. In the example below, the Employeeid “1” and EmployeeCode “AA” are used to index the documents in the collection.
An index can either be based on just one field in the collection, or it can be based on multiple fields in the collection. The below example shows an example of what field values could constitute an index in a collection.
Mongo grant readwrite any db update#
If there are frequent insert, delete and update operations carried out on documents, then the indexes would need to change that often, which would just be an overhead for the collection. Now even though from the introduction we have seen that indexes are good for queries, but having too many indexes can slow down other operations such as the Insert, Delete and Update operation. This partial set stores the value of a specific field or a set of fields ordered by the value of the field. Since the data is partial, it becomes easier to read this data. Indexes are special data sets which store a partial part of the collection’s data. But if you had indexes, MongoDB would use these indexes to limit the number of documents that had to be searched in the collection. If you had a collection with thousands of documents with no indexes, and then you query to find certain documents, then in such case MongoDB would need to scan the entire collection to find the documents. With the use of Indexes, performing queries in MongoDB becomes more efficient. In the above example, he is given read only permission to the “Marketing” database and readWrite permission to the “Sales” database.Indexes are very important in any database, and with MongoDB it’s no different.
Mongo grant readwrite any db code#
The above code snippet shows that a user called Mohan is created, and he is assigned multiple roles in multiple databases. For example, there is a the “read role” which only allows read only access to databases and then there is the “readwrite” role which provides read and write access to the database, which means that the user can issue the insert, delete and update commands on collections in that database. There is a whole list of role available in MongoDB. Managing usersįirst understand the roles which you need to define. The output shows that a user called “Employeeadmin” was created and that user has privileges only on the “Employee” database. If the command is executed successfully, the following Output will be shown: The db parameter specifies the database to which the user should have administrative privileges on.This role allows the user to have administrative privileges only to the database specified in the db option. The second step is to assign a role for the user which in this case since it needs to be a database administrator is assigned to the “userAdmin” role.
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