Create multiple indexes at a time

Question

I need to build five indexes in a large MongoDB collection. I am familiar with the makeIndex operation, but I don’t know how to create all five indexes with a single command. Is it possible to create this package in MongoDB?

Answer 1

It's pretty simple in the shell, there is an extension for the createIndexes collection, and you just pass the keys that you want to create indexes to.

 db.test.createIndexes([ { "a" : 1 }, { "b" : 1 }, { "c" : 1 }, { "d" : 1 }, { "e" : 1 } ]); 

Then it will give us the following

 > db.test.getIndexes() [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "test.test" }, { "v" : 2, "key" : { "a" : 1 }, "name" : "a_1", "ns" : "test.test" }, { "v" : 2, "key" : { "b" : 1 }, "name" : "b_1", "ns" : "test.test" }, { "v" : 2, "key" : { "c" : 1 }, "name" : "c_1", "ns" : "test.test" }, { "v" : 2, "key" : { "d" : 1 }, "name" : "d_1", "ns" : "test.test" }, { "v" : 2, "key" : { "e" : 1 }, "name" : "e_1", "ns" : "test.test" } ] > 

Answer 2

You are mistaken, Mongo has a createIndexes command since version 2.6 (released before 2014).

https://docs.mongodb.com/v3.0/reference/command/createIndexes/

The documentation says that this requires one pass through the collection, so it should be about 5 times faster.

Answer 3

There is no solution for this yet.

The background will prevent the database from being locked and allow other operations. But to start these operations, you will have to open a new mongo shell or run them asynchronously in the language of your choice (for example, js).

But if you need a strong consistency and you don't need to create background indexing ... you probably have to wait until your own MongoDB solution comes up.

Answer 4

I think this is not possible with a single command, but you can create your own script that will work the same way. If the size of your collection is large, I suggest that you separately create indexes with a background of true to reduce the likelihood of any locking problem.

 db.collection.ensureIndex( { a: 1 }, { background: true } )