# The Grand Operations When the Postgres beast receives your query, it doesn't just wildly guess what to do. It carefully constructs a service plan—a **Directed Acyclic Graph (DAG)** of operations. These are the verbs of our database. Some operations read data, some join things together, and some just sort things into neat little piles. To master PostgreSQL performance, you must learn to read these "Service Plans" and understand the mechanical costs of each station. --- ## ![[Operations/Table/_Table]] --- ## ![[Operations/Index/_Index]] --- ## ![[Operations/Page/_Page]] --- ## ![[Operations/ResultSet/_ResultSet]] --- ## ![[Operations/Distributed/_Distributed]] --- ## ![[Operations/Tuple/_Tuple]] --- ## ![[Operations/Other/_Other]]