Execute SQL on a profile (default profile when omitted). Returns the first page as compact {"columns":[...],"rows":[[...],...],"page":{"returned","has_more","estimated_rows","cursor"}}. When has_more is true, pass page.cursor to the fetch tool — the query is NOT re-executed; a server-side cursor is held open (stable snapshot). Placeholders: %s positional with the params array.

Fetch the next page from an open cursor returned by query. No re-execution: rows continue exactly where the last page ended. The cursor auto-closes when exhausted (has_more=false).

Close an open cursor (or all cursors when no token is given) to free its connection early.

List tables/views/matviews with estimated row counts and sizes (system schemas excluded). Optional name filter.

Describe one table: columns with types/nullability/defaults, constraints (PK/FK/unique/check), and indexes.

Show the query plan (EXPLAIN). Set analyze=true to actually run the statement and get real timings.

Orientation card for an unknown database: every table with row estimate and its column names in ONE compact call — use this before tables/describe round-trips. Optional table-name filter.

Find tables, columns, and functions by name OR by comment (pg_description — often the only documentation a schema has). Answers 'where is the customer email?' in one call.

Column statistics from pg_stats WITHOUT touching the table: null fraction, distinct count (negative = fraction of rows, -1 = unique), most common values with frequencies, histogram bounds, physical correlation. Replaces exploratory SELECT DISTINCT / GROUP BY scans.

Foreign keys of one table, both directions: what it references and what references it.

Shortest foreign-key path between two tables, rendered as a ready-to-use JOIN chain (up to 3 equally short paths). Use this instead of guessing joins on unfamiliar schemas.

Row count, estimate-first: instant planner estimate (no scan), optionally with a WHERE clause; exact=true runs a real count(*) under the statement timeout. Prefer the estimate.

A few genuinely random rows from a table (TABLESAMPLE on big tables — no scan, no physically-adjacent LIMIT bias).

List all connection profiles (DSNs password-redacted) and which one is the default.

Add or update a named connection profile at runtime and persist it. Tests the connection first (set test=false to skip). Profiles are read-only unless allow_writes=true. make_default=true switches the default profile. For a database only reachable via SSH, set ssh_host (an ssh destination or ~/.ssh/config alias; BatchMode, so keys/agent must work non-interactively) — a tunnel is opened automatically and kept alive; ssh_remote_host/ssh_remote_port default to the DSN's host/port as seen FROM the ssh host (usually 127.0.0.1:5432).

Remove a connection profile (open cursors on it are closed).

Test connectivity of a profile (default profile when omitted): server version and connect latency.

Server status: profiles with pool statistics, open cursors, configured limits, profiles file location.