merge: TSVector based search provider (!910)

View MR for information: https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/910

Approved-by: dakkar <dakkar@thenautilus.net>
Approved-by: Marie <github@yuugi.dev>

.config/example.yml

@@ -222,6 +222,19 @@ fulltextSearch:
   #   You need to install pgroonga and configure it as a PostgreSQL extension.
   #   In addition to the above, you need to create a pgroonga index on the text column of the note table.
   #   see: https://pgroonga.github.io/tutorial/
+  # - sqlTsvector
+  #   Use Postgres tsvectors.
+  #   You need to create a generated column and index on the note table to use this, followed by an ANALYZE on the table. Beware, this will take a while to be created and the database will remain locked during this process.
+  #   This also enables advanced search syntax, see documentation of websearch_to_tsquery: https://www.postgresql.org/docs/current/textsearch-controls.html#TEXTSEARCH-PARSING-QUERIES
+  #   Support for multiple languages is currently rather poor and will be improved once post languages become a feature.
+  #
+  #   Example to set up tsvectors for an English instance:
+  #   ALTER TABLE note ADD COLUMN tsvector_embedding tsvector GENERATED ALWAYS AS ( to_tsvector('english', COALESCE(text, '') || ' ' || COALESCE(cw, '') || ' ' || COALESCE(name, ''))) STORED;
+  #   CREATE INDEX vector_idx ON note USING GIN (tsvector_embedding);
+  #   ANALYZE note;
+  #
+  #   Note: You can opt to use a different dictionary for better results if your main instance language is not English.
+  #   To get a list, use "SELECT cfgname FROM pg_ts_config;" and replace 'english' with the desired dictionary name.
   # - meilisearch
   #   Use Meilisearch.
   #   You need to install Meilisearch and configure.

packages/backend/src/config.ts

@@ -254,7 +254,7 @@ export type Config = {
 	};
 };
 
-export type FulltextSearchProvider = 'sqlLike' | 'sqlPgroonga' | 'meilisearch';
+export type FulltextSearchProvider = 'sqlLike' | 'sqlPgroonga' | 'meilisearch' | 'sqlTsvector';
 
 const _filename = fileURLToPath(import.meta.url);
 const _dirname = dirname(_filename);

packages/backend/src/core/SearchService.ts

@@ -240,7 +240,8 @@ export class SearchService {
 	): Promise<MiNote[]> {
 		switch (this.provider) {
 			case 'sqlLike':
-			case 'sqlPgroonga': {
+			case 'sqlPgroonga':
+			case 'sqlTsvector': {
 				// ほとんど内容に差がないのでsqlLikeとsqlPgroongaを同じ処理にしている.
 				// 今後の拡張で差が出る用であれば関数を分ける.
 				return this.searchNoteByLike(q, me, opts, pagination);
@@ -280,6 +281,8 @@ export class SearchService {
 
 		if (this.config.fulltextSearch?.provider === 'sqlPgroonga') {
 			query.andWhere('note.text &@~ :q', { q });
+		} else if (this.config.fulltextSearch?.provider === 'sqlTsvector') {
+			query.andWhere('note.tsvector_embedding @@ websearch_to_tsquery(:q)', { q });
 		} else {
 			query.andWhere('note.text ILIKE :q', { q: `%${ sqlLikeEscape(q) }%` });
 		}