Operating a database

Running it in production

Beyond queries, a data-systems job expects operational fluency:

• Loading data fast — COPY streams CSV in/out far faster than row-by-row INSERT (psql's \copy does it client-side). INSERT ... SELECT and generate_series handle bulk transforms.
• Backups — pg_dump / pg_restore for logical backups; understand point-in-time recovery exists.
• Health — VACUUM/ANALYZE reclaim space and refresh planner statistics (autovacuum does this automatically); pg_stat_activity shows live queries.
• The psql client — \dt lists tables, \d table describes one, \du lists roles.
• Connections — apps use a connection pool (PgBouncer) because each Postgres connection has real overhead.

You don't need to be a DBA, but knowing these terms — and that they exist — is the difference between a junior who can operate and one who's stuck.