diff --git a/scripts/sql/probe.php b/scripts/sql/probe.php
new file mode 100755
index 0000000000..ac953e6dd1
--- /dev/null
+++ b/scripts/sql/probe.php
@@ -0,0 +1,69 @@
+#!/usr/bin/env php
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+$root = dirname(dirname(dirname(__FILE__)));
+require_once $root.'/scripts/__init_script__.php';
+
+$data = array();
+
+$conn_r = id(new PhabricatorUser())->establishConnection('r');
+$databases = queryfx_all($conn_r, 'SHOW DATABASES');
+foreach ($databases as $database) {
+  $name = head($database);
+  queryfx($conn_r, 'USE %C', $name);
+  $tables = queryfx_all(
+    $conn_r,
+    'SHOW TABLE STATUS');
+  $tables = ipull($tables, null, 'Name');
+  $data[$name] = $tables;
+}
+
+$totals = array_fill_keys(array_keys($data), 0);
+$overall = 0;
+
+foreach ($data as $db => $tables) {
+  foreach ($tables as $table => $info) {
+    $table_size = $info['Data_length'] + $info['Index_length'];
+
+    $data[$db][$table]['_totalSize'] = $table_size;
+    $totals[$db] += $table_size;
+    $overall += $table_size;
+  }
+}
+
+echo "APPROXIMATE TABLE SIZES\n";
+asort($totals);
+foreach ($totals as $db => $size) {
+  printf("%-32.32s %18s\n", $db, fmt($totals[$db], $overall));
+  $data[$db] = isort($data[$db], '_totalSize');
+  foreach ($data[$db] as $table => $info) {
+    printf("    %-28.28s %18s\n", $table, fmt($info['_totalSize'], $overall));
+  }
+}
+printf("%-32.32s %18s\n", 'TOTAL', fmt($overall, $overall));
+
+function fmt($n, $o) {
+
+  return sprintf(
+    '%8.8s MB  %5.5s%%',
+    number_format($n / (1024 * 1024), 1),
+    sprintf('%3.1f', 100 * ($n / $o)));
+}
+
+