feat: add migration for pg_textsearch

.env.sample

@@ -9,3 +9,5 @@ DB_SCHEMA=docs
 # OpenAI Embedding API Key
 OPENAI_API_KEY=sk-
 
+# Enable keyword search for TigerData docs
+ENABLE_KEYWORD_SEARCH=

migrations/1759876252954-add-tiger-textsearch-index.js

@@ -0,0 +1,52 @@
+import 'dotenv/config';
+import { Client } from 'pg';
+
+const schema = process.env.DB_SCHEMA || 'docs';
+
+// We only want to run this if keyword search is enabled, where this expects
+// that the user is using a Tiger Cloud backed database that has pg_textsearch
+// available.
+const keywordSearchEnabled = process.env.ENABLE_KEYWORD_SEARCH === 'true';
+
+export const description = 'Add textsearch indexes to tiger docs content column';
+
+export async function up() {
+  if (!keywordSearchEnabled) {
+    return;
+  }
+
+  const client = new Client();
+
+  try {
+    await client.connect();
+    await client.query(/* sql */ `
+      CREATE EXTENSION pg_textsearch;
+    `);
+    await client.query(/* sql */ `
+      CREATE INDEX IF NOT EXISTS ON ${schema}.timescaledb_chunks USING bm25(content) WITH (text_config='english');
+    `);
+  } catch (e) {
+    throw e;
+  } finally {
+    await client.end();
+  }
+}
+
+export async function down() {
+  if (!keywordSearchEnabled) {
+    return;
+  }
+
+  const client = new Client();
+
+  try {
+    await client.connect();
+    await client.query(/* sql */ `
+      DROP INDEX IF EXISTS ${schema}.timescale_chunks_content_idx;
+    `);
+  } catch (e) {
+    throw e;
+  } finally {
+    await client.end();
+  }
+}