fix: optimize GetProvisionerJobsByIDsWithQueuePosition query (#22724)

coderd/database/queries/provisionerjobs.sql

@@ -79,7 +79,7 @@ WHERE
 WITH filtered_provisioner_jobs AS (
 	-- Step 1: Filter provisioner_jobs
 	SELECT
-		id, created_at
+		id, created_at, tags
 	FROM
 		provisioner_jobs
 	WHERE
@@ -94,21 +94,32 @@ pending_jobs AS (
 	WHERE
 		job_status = 'pending'
 ),
-online_provisioner_daemons AS (
-	SELECT id, tags FROM provisioner_daemons pd
-	WHERE pd.last_seen_at IS NOT NULL AND pd.last_seen_at >= (NOW() - (@stale_interval_ms::bigint || ' ms')::interval)
+unique_daemon_tags AS (
+	SELECT DISTINCT tags FROM provisioner_daemons pd
+	WHERE pd.last_seen_at IS NOT NULL
+	  AND pd.last_seen_at >= (NOW() - (@stale_interval_ms::bigint || ' ms')::interval)
+),
+relevant_daemon_tags AS (
+	SELECT udt.tags
+	FROM unique_daemon_tags udt
+	WHERE EXISTS (
+		SELECT 1 FROM filtered_provisioner_jobs fpj
+		WHERE provisioner_tagset_contains(udt.tags, fpj.tags)
+	)
 ),
 ranked_jobs AS (
 	-- Step 3: Rank only pending jobs based on provisioner availability
 	SELECT
 		pj.id,
 		pj.created_at,
-		ROW_NUMBER() OVER (PARTITION BY opd.id ORDER BY pj.initiator_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'::uuid ASC, pj.created_at ASC) AS queue_position,
-		COUNT(*) OVER (PARTITION BY opd.id) AS queue_size
+		ROW_NUMBER() OVER (PARTITION BY rdt.tags ORDER BY pj.initiator_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'::uuid ASC, pj.created_at ASC) AS queue_position,
+		COUNT(*) OVER (PARTITION BY rdt.tags) AS queue_size
 	FROM
 		pending_jobs pj
-			INNER JOIN online_provisioner_daemons opd
-					ON provisioner_tagset_contains(opd.tags, pj.tags) -- Join only on the small pending set
+	INNER JOIN
+		relevant_daemon_tags rdt
+	ON
+		provisioner_tagset_contains(rdt.tags, pj.tags)
 ),
 final_jobs AS (
 	-- Step 4: Compute best queue position and max queue size per job