fix: use pg_trgm extension for indexing msg data->@type (#57)

migrations/committed/000002.sql

@@ -0,0 +1,10 @@
+--! Previous: sha1:5ad90bce5c5fb68d0a8f886b6c07fb280ccd2c42
+--! Hash: sha1:80425329666e5d20b5fbb7b6179f3d19acceeb76
+
+-- support for similarity of text using trigram matching
+CREATE extension IF NOT EXISTS pg_trgm;
+
+-- drop the previous index that wasn't being useful for LIKE operations
+-- and add a new index using gin_trgm_ops operator class from pg_trgm extension.
+DROP INDEX IF EXISTS msg_data_type_idx;
+CREATE INDEX IF NOT EXISTS msg_data_type_gin_idx ON msg USING gin  ((data->>'@type') gin_trgm_ops);

migrations/schema_snapshot.sql

@@ -44,6 +44,20 @@ CREATE EXTENSION IF NOT EXISTS pg_stat_statements WITH SCHEMA public;
 COMMENT ON EXTENSION pg_stat_statements IS 'track planning and execution statistics of all SQL statements executed';
 
 
+--
+-- Name: pg_trgm; Type: EXTENSION; Schema: -; Owner: -
+--
+
+CREATE EXTENSION IF NOT EXISTS pg_trgm WITH SCHEMA public;
+
+
+--
+-- Name: EXTENSION pg_trgm; Type: COMMENT; Schema: -; Owner: -
+--
+
+COMMENT ON EXTENSION pg_trgm IS 'text similarity measurement and index searching based on trigrams';
+
+
 --
 -- Name: pgcrypto; Type: EXTENSION; Schema: -; Owner: -
 --
@@ -579,10 +593,10 @@ CREATE INDEX flyway_schema_history_s_idx ON public.flyway_schema_history USING b
 
 
 --
--- Name: msg_data_type_idx; Type: INDEX; Schema: public; Owner: -
+-- Name: msg_data_type_gin_idx; Type: INDEX; Schema: public; Owner: -
 --
 
-CREATE INDEX msg_data_type_idx ON public.msg USING btree (((data -> '@type'::text)));
+CREATE INDEX msg_data_type_gin_idx ON public.msg USING gin (((data ->> '@type'::text)) public.gin_trgm_ops);
 
 
 --