from agno.agent import Agentfrom agno.knowledge.knowledge import Knowledgefrom agno.vectordb.pgvector import PgVectordb_url = "postgresql+psycopg://ai:ai@localhost:5532/ai"vector_db = PgVector(table_name="vectors", db_url=db_url)knowledge = Knowledge( name="My PG Vector Knowledge Base", description="This is a knowledge base that uses a PG Vector DB", vector_db=vector_db,)knowledge.add_content( name="Recipes", url="https://agno-public.s3.amazonaws.com/recipes/ThaiRecipes.pdf", metadata={"doc_type": "recipe_book"},)agent = Agent( knowledge=knowledge, search_knowledge=True, read_chat_history=True,)agent.print_response("How do I make pad thai?", markdown=True)vector_db.delete_by_name("Recipes")vector_db.delete_by_metadata({"doc_type": "recipe_book"})