Feat: Add pg_bigm for keyword search in pgvector (#13876)

Signed-off-by: Yuichiro Utsumi <utsumi.yuichiro@fujitsu.com>

api/configs/middleware/vdb/pgvector_config.py

@@ -43,3 +43,8 @@ class PGVectorConfig(BaseSettings):
         description="Max connection of the PostgreSQL database",
         default=5,
     )
+
+    PGVECTOR_PG_BIGM: bool = Field(
+        description="Whether to use pg_bigm module for full text search",
+        default=False,
+    )