postgres trained

Start from the application's data contract and observed query workload. Schema, indexes, transaction semantics, and connection limits are one system; changing one can move cost to writes or operations. Use the project's existing database and provider unless a measured requirement justifies a change.

On a safe PostgreSQL connection, inspect a read-only plan with execution data:

EXPLAIN ANALYZE executes its statement, including writes if the statement mutates data; use plain EXPLAIN first for unknown or consequential commands (PostgreSQL EXPLAIN).

• Inspect real query plans, row estimates, and buffer use before creating an index; verify improvement under representative data (PostgreSQL EXPLAIN).
• Keep foreign keys for integrity; assess an index on the referencing side from its actual join and delete/update workload (PostgreSQL constraints).
• Let normal autovacuum operate; investigate table-specific churn or stale statistics before manual maintenance (PostgreSQL routine vacuuming).
• Use the project's migration and backup tooling. A successful backup command alone does not prove restoration; test a restore in a safe target.

PostgreSQL provides transactions, constraints, rich indexing, and readable plans. When PlanetScale is the actual provider, its operational guidance adds useful depth.

Every index adds write and storage cost. Plan estimates depend on statistics and data distribution. Connection pools and managed-provider limits vary by deployment; generic values are unsafe defaults.

• PlanetScale's hosting recommendation is vendor marketing, not comparative evidence for a specific workload.
• Use the project's migration and backup tools; this guru does not install a second operational layer over the owning stack.
• VACUUM FULL has materially different locking and disk behavior from ordinary VACUUM; read the versioned command docs before using it (PostgreSQL VACUUM).

No version-specific PostgreSQL defect is known here.

The read-only plan example runs as written. On a local PostgreSQL 16.14 server, BEGIN READ ONLY; EXPLAIN (ANALYZE, BUFFERS) SELECT 1; ROLLBACK; returns a plan with execution and buffer data. That proves the example on one server; it is not a tuned application workload.