Reset function for VectorDBs (#2584)

mem0/vector_stores/pgvector.py

@@ -286,3 +286,9 @@ class PGVector(VectorStoreBase):
             self.cur.close()
         if hasattr(self, "conn"):
             self.conn.close()
+            
+    def reset(self):
+        """Reset the index by deleting and recreating it."""
+        logger.warning(f"Resetting index {self.collection_name}...")
+        self.delete_col()
+        self.create_col(self.embedding_model_dims)