+ list($low, $high) = XDB::fetchOneRow(
+ "SELECT MIN(uid), MAX(uid)
+ FROM #x5dat#.accounts
+ WHERE state = {?} AND is_admin = {?}",
+ $state, $isAdmin);
+
+ $batchSize = 100;
+ $nbBatches = 0;
+ $affectedRows = 0;
+
+ // Run in batches.
+ for ($lowUID = $low; $lowUID <= $high; $lowUID += $batchSize) {
+
+ // Slight optimization for last loop: adjust to exactly what's necessary.
+ $highUID = min($high + 1, $lowUID + $batchSize);
+
+ XDB::execute(
+ "DELETE s
+ FROM log_sessions AS s
+ JOIN (SELECT a.uid,
+ (SELECT us.start
+ FROM log_sessions AS us
+ WHERE us.uid = a.uid AND (us.suid IS NULL OR us.suid = 0)
+ ORDER BY us.start DESC
+ LIMIT {?}, 1) AS no_discard_limit
+ FROM #x5dat#.accounts AS a
+ WHERE a.state = {?} AND a.is_admin = {?}
+ AND a.uid >= {?} AND a.uid < {?}
+ ORDER BY a.uid ASC) AS ut ON (ut.uid = s.uid)
+ WHERE s.start < DATE_SUB(NOW(), INTERVAL {?} MONTH)
+ AND s.start < ut.no_discard_limit",
+ $minimalBacklog - 1, $state, $isAdmin, $lowUID, $highUID, $retentionPeriod);
+
+ $nbBatches += 1;
+ $affectedRows += XDB::affectedRows();
+ }
+
+ $duration = time() - $begin;
+ echo "Users with permission '$userPerms': removed $affectedRows sessions in $duration seconds ($nbBatches batches).\n";