Explore the statistics: a query log to drill down by client, name, view and more; storage on the dashboard

jarld keeps every answer for a while (stats.retention.queries, default 7 days) in the statistics database: time, client, view, name, type, result and what blocked it. Every client, name, view, record type, result and blocklist on the Statistics page leads to an explore page for it: answers over time, the top values of every other dimension (each a link that narrows further) and the latest answers. GET /stats/explore.

The dashboard shows the size of Jarl's databases (and the query log's rows) and, per disk Jarl uses, how full it is and the databases' share.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/stats/store.go

@@ -45,6 +45,21 @@ var schema = []string{
 		PRIMARY KEY (res, ts, kind, key)
 	) WITHOUT ROWID;
 	CREATE TABLE meta (key TEXT PRIMARY KEY, value TEXT NOT NULL);`,
+	// 2: the query log, every answer for a while (stats.query_retention),
+	// for drilling down: what a client asked, who asked for a name
+	// (docs/stats.md#exploring).
+	`CREATE TABLE queries (
+		ts      INTEGER NOT NULL,
+		client  TEXT NOT NULL,
+		view    TEXT NOT NULL,
+		name    TEXT NOT NULL,
+		type    TEXT NOT NULL,
+		rcode   TEXT NOT NULL,
+		blocked TEXT NOT NULL DEFAULT ''
+	);
+	CREATE INDEX queries_ts ON queries (ts);
+	CREATE INDEX queries_client ON queries (client, ts);
+	CREATE INDEX queries_name ON queries (name, ts);`,
 }
 
 // OpenStore opens (creating if needed) the statistics database. Use
@@ -123,8 +138,25 @@ type Batch struct {
 	counters []counterRow
 	tops     []topsWrite
 	meta     map[string]string
+	queries  []QueryRow
 }
 
+// QueryRow is one answer in the query log.
+type QueryRow struct {
+	Time    int64  `json:"ts"` // Unix seconds
+	Client  string `json:"client"`
+	View    string `json:"view"` // "_default" without views
+	Name    string `json:"name"`
+	Type    string `json:"type"`
+	RCode   string `json:"rcode"`
+	Blocked string `json:"blocked,omitempty"` // the blocklist (or "rules") that blocked it
+	// ClientName is the client's host name (set by the API).
+	ClientName string `json:"client_name,omitempty"`
+}
+
+// AddQueries adds answers to the query log.
+func (b *Batch) AddQueries(rows []QueryRow) { b.queries = append(b.queries, rows...) }
+
 type counterRow struct {
 	res   string
 	ts    int64
@@ -220,9 +252,39 @@ func (s *Store) Commit(ctx context.Context, b *Batch) error {
 			return err
 		}
 	}
+	if len(b.queries) > 0 {
+		st, err := tx.PrepareContext(ctx, `INSERT INTO queries (ts, client, view, name, type, rcode, blocked) VALUES (?, ?, ?, ?, ?, ?, ?)`)
+		if err != nil {
+			return err
+		}
+		for _, q := range b.queries {
+			if _, err := st.ExecContext(ctx, q.Time, q.Client, q.View, q.Name, q.Type, q.RCode, q.Blocked); err != nil {
+				st.Close()
+				return err
+			}
+		}
+		st.Close()
+	}
 	return tx.Commit()
 }
 
+// PruneQueries deletes the query log's answers older than before (Unix
+// time), a slice at a time so the database isn't locked for long.
+func (s *Store) PruneQueries(ctx context.Context, before int64) (int64, error) {
+	var n int64
+	for {
+		r, err := s.db.ExecContext(ctx, `DELETE FROM queries WHERE rowid IN (SELECT rowid FROM queries WHERE ts < ? LIMIT 50000)`, before)
+		if err != nil {
+			return n, err
+		}
+		c, _ := r.RowsAffected()
+		n += c
+		if c < 50000 {
+			return n, nil
+		}
+	}
+}
+
 // Meta returns a stored value ("" if unset).
 func (s *Store) Meta(ctx context.Context, key string) (string, error) {
 	var v string