FT.SPELLCHECK
FT.SPELLCHECK index query [DISTANCE distance] [TERMS INCLUDE | EXCLUDE dictionary [terms [terms ...]]] [DIALECT dialect]
- Available in:
- Redis Stack / Search 1.4.0
- Time complexity:
- O(1)
Perform spelling correction on a query, returning suggestions for misspelled terms
Required arguments
index
is index with the indexed terms.
query
is search query.
See Spellchecking for more details.
Optional arguments
TERMS
specifies an inclusion (INCLUDE) or exclusion (EXCLUDE) of a custom dictionary. To learn more about managing custom dictionaries, see FT.DICTADD, FT.DICTDEL, and FT.DICTDUMP.
You can specify multiple inclusion and exclusion TERMS.
DISTANCE
is maximum Levenshtein distance for spelling suggestions (default: 1, max: 4).
DIALECT {dialect_version}
selects the dialect version under which to execute the query. If not specified, the query will execute under the default dialect version set during module initial loading or via FT.CONFIG SET command.
Return
FT.SPELLCHECK returns an array reply, in which each element represents a misspelled term from the query. The misspelled terms are ordered by their order of appearance in the query.
Each misspelled term, in turn, is a 3-element array consisting of the constant string TERM, the term itself and an array of suggestions for spelling corrections.
Each element in the spelling corrections array consists of the score of the suggestion and the suggestion itself. The suggestions array, per misspelled term, is ordered in descending order by score.
The score is calculated by dividing the number of documents in which the suggested term exists by the total number of documents in the index. Results can be normalized by dividing scores by the highest score.
Examples
Perform spelling correction on a query
127.0.0.1:6379> FT.SPELLCHECK idx held DISTANCE 2
1) 1) "TERM"
2) "held"
3) 1) 1) "0.66666666666666663"
2) "hello"
2) 1) "0.33333333333333331"
2) "help"See also
FT.CONFIG SET | FT.DICTADD | FT.DICTDEL | FT.DICTDUMP