A list of indices in MongoDB?

Is there a way to see a list of indices on a collection in mongodb in shell? i read through http://www.mongodb.org/display/DOCS/Indexes but i dont 开发者_如何转开发see anything

From the shell:

db.test.getIndexes()

For shell help you should try:

help;
db.help();
db.test.help();

If you want to list all indexes across collections:

db.getCollectionNames().forEach(function(collection) {
   indexes = db.getCollection(collection).getIndexes();
   print("Indexes for " + collection + ":");
   printjson(indexes);
});

And if you want to get list of all indexes in your database:

use "yourdbname"

db.system.indexes.find()

Make sure you use your collection:

db.collection.getIndexes()

http://docs.mongodb.org/manual/administration/indexes/#information-about-indexes

You can also output all your indexes together with their size:

db.collectionName.stats().indexSizes

Also check that db.collectionName.stats() gives you a lot of interesting information like paddingFactor, size of the collection and number of elements inside of it.

Taking this one step further, if you'd like to find all indexes on all collections, this script (modified from Juan Carlos Farah's script here) gives you some useful output, including a JSON printout of the index details:

 // Switch to admin database and get list of databases.
db = db.getSiblingDB("admin");
dbs = db.runCommand({ "listDatabases": 1}).databases;


// Iterate through each database and get its collections.
dbs.forEach(function(database) {
db = db.getSiblingDB(database.name);
cols = db.getCollectionNames();

// Iterate through each collection.
cols.forEach(function(col) {

    //Find all indexes for each collection
     indexes = db[col].getIndexes();

     indexes.forEach(function(idx) {
        print("Database:" + database.name + " | Collection:" +col+ " | Index:" + idx.name);
        printjson(indexes);
         });


    });

});

Using an old version of MongoDB here but one of the top answers in this question here did not work for me. This one worked:

db.getCollectionNames().forEach(function(collection) {
    print("Collection: '" + collection);
    print(db.getCollection(collection).getIndexes())
});