From 8091dfedbea04f8697c8840e0c522728817c3676 Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Sun, 2 Jan 2022 17:19:24 -0300
Subject: [PATCH] use generated columns and gin array indexes to query tags
 better.

---
 basic/postgresql.go | 13 ++++++++++---
 basic/query.go      | 28 +++++++++++++---------------
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/basic/postgresql.go b/basic/postgresql.go
index 0fd9056..d5c7d1f 100644
--- a/basic/postgresql.go
+++ b/basic/postgresql.go
@@ -13,6 +13,12 @@ func initDB(dburl string) (*sqlx.DB, error) {
 	}
 
 	_, err = db.Exec(`
+CREATE FUNCTION tags_to_tagvalues(jsonb) RETURNS text[]
+    AS 'SELECT array_agg(t->>1) FROM (SELECT jsonb_array_elements($1) AS t)s;'
+    LANGUAGE SQL
+    IMMUTABLE
+    RETURNS NULL ON NULL INPUT;
+
 CREATE TABLE IF NOT EXISTS event (
   id text NOT NULL,
   pubkey text NOT NULL,
@@ -20,14 +26,15 @@ CREATE TABLE IF NOT EXISTS event (
   kind integer NOT NULL,
   tags jsonb NOT NULL,
   content text NOT NULL,
-  sig text NOT NULL
+  sig text NOT NULL,
+
+  tagvalues text[] GENERATED ALWAYS AS (tags_to_tagvalues(tags)) STORED
 );
 
 CREATE UNIQUE INDEX IF NOT EXISTS ididx ON event (id);
 CREATE UNIQUE INDEX IF NOT EXISTS pubkeytimeidx ON event (pubkey, created_at);
+CREATE INDEX IF NOT EXISTS arbitrarytagvalues ON event USING gin (tagvalues);
     `)
 	log.Print(err)
 	return db, nil
 }
-
-const tagConditions = `jsonb_path_match(tags, '$[*][1] == $value', jsonb_build_object('value', ?::text))`
diff --git a/basic/query.go b/basic/query.go
index 4ef44dc..933ddb6 100644
--- a/basic/query.go
+++ b/basic/query.go
@@ -87,40 +87,38 @@ func (b *BasicRelay) QueryEvents(
 		conditions = append(conditions, `kind IN (`+strings.Join(inkinds, ",")+`)`)
 	}
 
+	tagQuery := make([]string, 0, 1)
 	if filter.TagE != nil {
 		if len(filter.TagE) > 10 {
 			// too many tags, fail everything
 			return
 		}
-
 		if len(filter.TagE) == 0 {
 			// #e being [] mean you won't get anything
 			return
 		}
-		innerConditions := make([]string, len(filter.TagE))
-		for _, e := range filter.TagE {
-			innerConditions = append(innerConditions, tagConditions)
-			params = append(params, e)
-		}
-		conditions = append(conditions, strings.Join(innerConditions, " OR "))
+		tagQuery = append(tagQuery, filter.TagE...)
 	}
-
 	if filter.TagP != nil {
 		if len(filter.TagP) > 10 {
 			// too many tags, fail everything
 			return
 		}
-
 		if len(filter.TagP) == 0 {
-			// #p being [] mean you won't get anything
+			// #e being [] mean you won't get anything
 			return
 		}
-		innerConditions := make([]string, len(filter.TagP))
-		for _, p := range filter.TagP {
-			innerConditions = append(innerConditions, tagConditions)
-			params = append(params, p)
+		tagQuery = append(tagQuery, filter.TagP...)
+	}
+
+	if len(tagQuery) > 0 {
+		arrayBuild := make([]string, len(tagQuery))
+		for i, tagValue := range tagQuery {
+			arrayBuild[i] = "?"
+			params = append(params, tagValue)
 		}
-		conditions = append(conditions, strings.Join(innerConditions, " OR "))
+		conditions = append(conditions,
+			"tagvalues && ARRAY["+strings.Join(arrayBuild, ",")+"]")
 	}
 
 	if filter.Since != 0 {