&^> operator

Since 1.0.9.

Summary

This operator uses v2 operator class. It doesn't provide backward compatibility until PGroonga 2.0.0. Use it carefully.

&^> operator performs prefix search.

Prefix search is useful for implementing input completion.

Syntax

column &^> prefix

column is a column to be searched. It's text[] type.

prefix is a prefix to be found. It's text type.

The operator returns true when one of the column values start with prefix.

Usage

Here are sample schema and data for examples:

CREATE TABLE tags (
  name text PRIMARY KEY,
  aliases text[]
);

CREATE INDEX pgroonga_tag_aliases_index ON tags
  USING pgroonga (aliases pgroonga.text_array_term_search_ops_v2);
INSERT INTO tags VALUES ('PostgreSQL', ARRAY['PostgreSQL', 'PG']);
INSERT INTO tags VALUES ('Groonga',    ARRAY['Groonga', 'grn']);
INSERT INTO tags VALUES ('PGroonga',   ARRAY['PGroonga', 'pgrn']);

You can perform prefix search with prefix by &^> operator:

SELECT * FROM tags WHERE aliases &^> 'pg';
--     name    |     aliases     
-- ------------+-----------------
--  PostgreSQL | {PostgreSQL,PG}
--  PGroonga   | {PGroonga,pgrn}
-- (2 rows)

See also