MongoDB Documentation, Release 3.0.4 Supported Languages and Stop Words sparse Property Restrictions As with all compound text indexes (page 501), since the a precedes the text index key, in order to perform a $text search with this index, the query predicate must include an equality match conditions a . For information on compound text indexes, see Compound Text Indexes (page 501). MongoDB supports text search for various languages. text indexes drop language-specific stop words (e.g. in English, “the”, “an”, “a”, “and”, etc.) and uses simple language-specific suffix stemming. For a list of the supported languages, see Text Search Languages (page 556). If you specify a language value of "none" , then the text index uses simple tokenization with no list of stop words and no stemming. For the Latin alphabet, text indexes are case insensitive for non-diacritics; i.e. case insensitive for [A-z] . For all other characters, text indexes treat them as distinct. To specify a language for the text index, see Specify a Language for Text Index (page 540). For a compound index that includes a text index key along with keys of other types, only the text index field determine whether the index references a document. The other keys do not determine whether the index references the documents or not. Text Search and Hints You cannot use hint() if the query includes a $text query expression. Text Index and Sort Sort operations cannot obtain sort order from a text index, even from a compound text index (page 501); i.e. sort operations cannot use the ordering in the text index. Compound Index A compound index (page 489) can include a text index key in combination with ascend- ing/descending index keys. However, these compound indexes have the following restrictions: See also Text Index and Sort (page 501) for additional limitations. For an example of a compound text index, see Limit the Number of Entries Scanned (page 544). Drop a Text Index To drop a text index, pass the name of the index to the db.collection.dropIndex() method. To get the name of the index, run the getIndexes() method. For information on the default naming scheme for text indexes as well as overriding the default name, see Specify Name for text Index (page 542). 8.2. Index Concepts • A compound text index cannot include any other special index types, such as multi-key (page 491) or geospa- tial (page 495) index fields. • If the compound text index includes keys preceding the text index key, to perform a $text search, the query predicate must include equality match conditions on the preceding keys. text indexes are sparse (page 505) by default and ignores the sparse: true (page 505) option. If a document lacks a text index field (or the field is null or an empty array), MongoDB does not add an entry for the document to the text index. For inserts, MongoDB inserts the document but does not add to the text index. 501