Fix performance and precision of TopSongs

db/migration/20201021135455_add_media_file_artist_index.go

@@ -0,0 +1,23 @@
+package migration
+
+import (
+	"database/sql"
+
+	"github.com/pressly/goose"
+)
+
+func init() {
+	goose.AddMigration(Up20201021135455, Down20201021135455)
+}
+
+func Up20201021135455(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+create index if not exists media_file_artist_id
+	on media_file (artist_id);
+`)
+	return err
+}
+
+func Down20201021135455(tx *sql.Tx) error {
+	return nil
+}