Deleting an Index

Review the code below, which demonstrates how to delete indexes in a collection.

View the Indexes used in a Collection

Use getIndexes() to see all the indexes created in a collection. There is always a default index in every collection on _id field. This index is used by MongoDB internally and cannot be deleted.

db.customers.getIndexes()

Delete an Index

Use dropIndex() to delete an existing index from a collection. Within the parentheses of dropIndex(), include an object representing the index key or provide the index name as a string.

Delete index by name:

db.customers.dropIndex(
  'active_1_birthdate_-1_name_1'
)

Delete index by key:

db.customers.dropIndex({
  active:1,
  birthdate:-1, 
  name:1
})

Delete Indexes

Use dropIndexes() to delete all the indexes from a collection, with the exception of the default index on _id.

db.customers.dropIndexes()

The dropIndexes() command also can accept an array of index names as a parameter to delete a specific list of indexes.

db.collection.dropIndexes([
  'index1name', 'index2name', 'index3name'
  ])