diff --git a/db/core.php b/db/core.php
index eb90ca85fd..695a3e3aa0 100644
--- a/db/core.php
+++ b/db/core.php
@@ -13,7 +13,8 @@
  * MySQL 'timestamp' columns were formerly used for 'modified' files for their
  * auto-updating properties. This didn't play well with changes to cache usage
  * in 0.9.x, as we don't know the timestamp value at INSERT time and never
- * have a chance to load it up again before caching.
+ * have a chance to load it up again before caching. For now I'm leaving them
+ * in, but we may want to clean them up later.
  *
  * Current code should be setting 'created' and 'modified' fields explicitly;
  * this also avoids mismatches between server and client timezone settings.
@@ -44,7 +45,7 @@ $schema['profile'] = array(
         'location_ns' => array('type' => 'int', 'description' => 'namespace for location'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'indexes' => array(
@@ -65,7 +66,7 @@ $schema['avatar'] = array(
         'filename' => array('type' => 'varchar', 'length' => 255, 'description' => 'local filename, if local'),
         'url' => array('type' => 'varchar', 'length' => 255, 'description' => 'avatar location'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('profile_id', 'width', 'height'),
     'unique keys' => array(
@@ -85,7 +86,7 @@ $schema['sms_carrier'] = array(
         'name' => array('type' => 'varchar', 'length' => 64, 'description' => 'name of the carrier'),
         'email_pattern' => array('type' => 'varchar', 'length' => 255, 'not null' => true, 'description' => 'sprintf pattern for making an email address from a phone number'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -123,7 +124,7 @@ $schema['user'] = array(
         'viewdesigns' => array('type' => 'int', 'size' => 'tiny', 'default' => 1, 'description' => 'whether to view user-provided designs'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -151,7 +152,7 @@ $schema['remote_profile'] = array(
         'postnoticeurl' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL we use for posting notices'),
         'updateprofileurl' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL we use for updates to this profile'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -171,7 +172,7 @@ $schema['subscription'] = array(
         'token' => array('type' => 'varchar', 'length' => 255, 'description' => 'authorization token'),
         'secret' => array('type' => 'varchar', 'length' => 255, 'description' => 'token secret'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('subscriber', 'subscribed'),
     'indexes' => array(
@@ -190,7 +191,7 @@ $schema['notice'] = array(
         'rendered' => array('type' => 'text', 'description' => 'HTML version of the content'),
         'url' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL of any attachment (image, video, bookmark, whatever)'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
         'reply_to' => array('type' => 'int', 'description' => 'notice replied to (usually a guess)'),
         'is_local' => array('type' => 'int', 'size' => 'tiny', 'default' => 0, 'description' => 'notice was generated by a user'),
         'source' => array('type' => 'varchar', 'length' => 32, 'description' => 'source of comment, like "web", "im", or "clientname"'),
@@ -229,7 +230,7 @@ $schema['notice_source'] = array(
         'name' => array('type' => 'varchar', 'length' => 255, 'not null' => true, 'description' => 'name of the source'),
         'url' => array('type' => 'varchar', 'length' => 255, 'not null' => true, 'description' => 'url to link to'),
         'notice_id' => array('type' => 'int', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('code'),
 );
@@ -238,7 +239,7 @@ $schema['reply'] = array(
     'fields' => array(
         'notice_id' => array('type' => 'int', 'not null' => true, 'description' => 'notice that is the reply'),
         'profile_id' => array('type' => 'int', 'not null' => true, 'description' => 'profile replied to'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
         'replied_id' => array('type' => 'int', 'description' => 'notice replied to (not used, see notice.reply_to)'),
     ),
     'primary key' => array('notice_id', 'profile_id'),
@@ -257,7 +258,7 @@ $schema['fave'] = array(
     'fields' => array(
         'notice_id' => array('type' => 'int', 'not null' => true, 'description' => 'notice that is the favorite'),
         'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user who likes this notice'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('notice_id', 'user_id'),
     'foreign keys' => array(
@@ -281,7 +282,7 @@ $schema['consumer'] = array(
         'seed' => array('type' => 'char', 'length' => 32, 'not null' => true, 'description' => 'seed for new tokens by this consumer'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('consumer_key'),
 );
@@ -298,7 +299,7 @@ $schema['token'] = array(
         'verified_callback' => array('type' => 'varchar', 'length' => 255, 'description' => 'verified callback URL for OAuth 1.0a'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('consumer_key', 'tok'),
     'foreign keys' => array(
@@ -315,7 +316,7 @@ $schema['nonce'] = array(
         'ts' => array('type' => 'datetime', 'not null' => true, 'description' => 'timestamp sent'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('consumer_key', 'ts', 'nonce'),
 );
@@ -336,7 +337,7 @@ $schema['oauth_application'] = array(
         'type' => array('type' => 'int', 'size' => 'tiny', 'default' => 0, 'description' => 'type of app, 1 = browser, 2 = desktop'),
         'access_type' => array('type' => 'int', 'size' => 'tiny', 'default' => 0, 'description' => 'default access type, bit 1 = read, bit 2 = write'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -355,7 +356,7 @@ $schema['oauth_application_user'] = array(
         'access_type' => array('type' => 'int', 'size' => 'tiny', 'default' => 0, 'description' => 'access type, bit 1 = read, bit 2 = write'),
         'token' => array('type' => 'varchar', 'length' => 255, 'description' => 'request or access token'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('profile_id', 'application_id'),
     'foreign keys' => array(
@@ -398,7 +399,7 @@ $schema['confirm_address'] = array(
         'address_type' => array('type' => 'varchar', 'length' => 8, 'not null' => true, 'description' => 'address type ("email", "xmpp", "sms")'),
         'claimed' => array('type' => 'datetime', 'description' => 'date this was claimed for queueing'),
         'sent' => array('type' => 'datetime', 'description' => 'date this was sent for queueing'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('code'),
     'foreign keys' => array(
@@ -410,7 +411,7 @@ $schema['remember_me'] = array(
     'fields' => array(
         'code' => array('type' => 'varchar', 'length' => 32, 'not null' => true, 'description' => 'good random code'),
         'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user who is logged in'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('code'),
     'foreign keys' => array(
@@ -457,7 +458,7 @@ $schema['foreign_service'] = array(
         'name' => array('type' => 'varchar', 'length' => 32, 'not null' => true, 'description' => 'name of the service'),
         'description' => array('type' => 'varchar', 'length' => 255, 'description' => 'description'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -472,7 +473,7 @@ $schema['foreign_user'] = array(
         'uri' => array('type' => 'varchar', 'length' => 255, 'not null' => true, 'description' => 'identifying URI'),
         'nickname' => array('type' => 'varchar', 'length' => 255, 'description' => 'nickname on foreign service'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id', 'service'),
     'foreign keys' => array(
@@ -495,7 +496,7 @@ $schema['foreign_link'] = array(
         'last_noticesync' => array('type' => 'datetime', 'description' => 'last time notices were imported'),
         'last_friendsync' => array('type' => 'datetime', 'description' => 'last time friends were imported'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('user_id', 'foreign_id', 'service'),
     'foreign keys' => array(
@@ -555,7 +556,7 @@ $schema['message'] = array(
         'rendered' => array('type' => 'text', 'description' => 'HTML version of the content'),
         'url' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL of any attachment (image, video, bookmark, whatever)'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
         'source' => array('type' => 'varchar', 'length' => 32, 'description' => 'source of comment, like "web", "im", or "clientname"'),
     ),
     'primary key' => array('id'),
@@ -598,7 +599,7 @@ $schema['profile_tag'] = array(
         'tagger' => array('type' => 'int', 'not null' => true, 'description' => 'user making the tag'),
         'tagged' => array('type' => 'int', 'not null' => true, 'description' => 'profile tagged'),
         'tag' => array('type' => 'varchar', 'length' => 64, 'not null' => true, 'description' => 'hash tag associated with this notice'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date the tag was added'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date the tag was added'),
     ),
     'primary key' => array('tagger', 'tagged', 'tag'),
     'foreign keys' => array(
@@ -616,7 +617,7 @@ $schema['profile_block'] = array(
     'fields' => array(
         'blocker' => array('type' => 'int', 'not null' => true, 'description' => 'user making the block'),
         'blocked' => array('type' => 'int', 'not null' => true, 'description' => 'profile that is blocked'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date of blocking'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date of blocking'),
     ),
     'foreign keys' => array(
         'profile_block_blocker_fkey' => array('user', array('blocker' => 'id')),
@@ -642,7 +643,7 @@ $schema['user_group'] = array(
         'design_id' => array('type' => 'int', 'description' => 'id of a design'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
 
         'uri' => array('type' => 'varchar', 'length' => 255, 'description' => 'universal identifier'),
         'mainpage' => array('type' => 'varchar', 'length' => 255, 'description' => 'page for group info to link to'),
@@ -666,7 +667,7 @@ $schema['group_member'] = array(
         'is_admin' => array('type' => 'int', 'size' => 'tiny', 'default' => 0, 'description' => 'is this user an admin?'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('group_id', 'profile_id'),
     'foreign keys' => array(
@@ -724,7 +725,7 @@ $schema['file'] = array(
         'protected' => array('type' => 'int', 'description' => 'true when URL is private (needs login)'),
         'filename' => array('type' => 'varchar', 'length' => 255, 'description' => 'if a local file, name of the file'),
 
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -747,7 +748,7 @@ $schema['file_oembed'] = array(
         'author_name' => array('type' => 'varchar', 'length' => 50, 'description' => 'author name for this oEmbed resource'),
         'author_url' => array('type' => 'varchar', 'length' => 255, 'description' => 'author URL for this oEmbed resource'),
         'url' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL for this oEmbed resource when applicable (photo, link)'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('file_id'),
     'foreign keys' => array(
@@ -761,7 +762,7 @@ $schema['file_redirection'] = array(
         'file_id' => array('type' => 'int', 'description' => 'short URL for what URL/file'),
         'redirections' => array('type' => 'int', 'description' => 'redirect count'),
         'httpcode' => array('type' => 'int', 'description' => 'HTTP status code (20x, 30x, etc.)'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('url'),
     'foreign keys' => array(
@@ -775,7 +776,7 @@ $schema['file_thumbnail'] = array(
         'url' => array('type' => 'varchar', 'length' => 255, 'description' => 'URL of thumbnail'),
         'width' => array('type' => 'int', 'description' => 'width of thumbnail'),
         'height' => array('type' => 'int', 'description' => 'height of thumbnail'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('file_id'),
     'foreign keys' => array(
@@ -790,7 +791,7 @@ $schema['file_to_post'] = array(
     'fields' => array(
         'file_id' => array('type' => 'int', 'not null' => true, 'description' => 'id of URL/file'),
         'post_id' => array('type' => 'int', 'not null' => true, 'description' => 'id of the notice it belongs to'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('file_id', 'post_id'),
     'foreign keys' => array(
@@ -821,7 +822,7 @@ $schema['group_block'] = array(
         'group_id' => array('type' => 'int', 'not null' => true, 'description' => 'group profile is blocked from'),
         'blocked' => array('type' => 'int', 'not null' => true, 'description' => 'profile that is blocked'),
         'blocker' => array('type' => 'int', 'not null' => true, 'description' => 'user making the block'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date of blocking'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date of blocking'),
     ),
     'primary key' => array('group_id', 'blocked'),
     'foreign keys' => array(
@@ -835,7 +836,7 @@ $schema['group_alias'] = array(
     'fields' => array(
         'alias' => array('type' => 'varchar', 'length' => 64, 'not null' => true, 'description' => 'additional nickname for the group'),
         'group_id' => array('type' => 'int', 'not null' => true, 'description' => 'group profile is blocked from'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date alias was created'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date alias was created'),
     ),
     'primary key' => array('alias'),
     'foreign keys' => array(
@@ -851,7 +852,7 @@ $schema['session'] = array(
         'id' => array('type' => 'varchar', 'length' => 32, 'not null' => true, 'description' => 'session ID'),
         'session_data' => array('type' => 'text', 'description' => 'session data'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'indexes' => array(
@@ -902,7 +903,7 @@ $schema['location_namespace'] = array(
         'id' => array('type' => 'int', 'not null' => true, 'description' => 'identity for this namespace'),
         'description' => array('type' => 'varchar', 'length' => 255, 'description' => 'description of the namespace'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date the record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
 );
@@ -912,7 +913,7 @@ $schema['login_token'] = array(
         'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user owning this token'),
         'token' => array('type' => 'char', 'length' => 32, 'not null' => true, 'description' => 'token useable for logging in'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('user_id'),
     'foreign keys' => array(
@@ -925,7 +926,7 @@ $schema['user_location_prefs'] = array(
         'user_id' => array('type' => 'int', 'not null' => true, 'description' => 'user who has the preference'),
         'share_location' => array('type' => 'int', 'size' => 'tiny', 'default' => 1, 'description' => 'Whether to share location data'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('user_id'),
     'foreign keys' => array(
@@ -955,7 +956,7 @@ $schema['user_im_prefs'] = array(
         'microid' => array('type' => 'int', 'size' => 'tiny', 'not null' => true, 'default' => 1, 'description' => 'Publish a MicroID'),
         'updatefrompresence' => array('type' => 'int', 'size' => 'tiny', 'not null' => true, 'default' => 0, 'description' => 'Send replies from people not subscribed to.'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('user_id', 'transport'),
     'unique keys' => array(
@@ -971,7 +972,7 @@ $schema['conversation'] = array(
         'id' => array('type' => 'serial', 'not null' => true, 'description' => 'unique identifier'),
         'uri' => array('type' => 'varchar', 'length' => 225, 'description' => 'URI of the conversation'),
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('id'),
     'unique keys' => array(
@@ -986,7 +987,7 @@ $schema['local_group'] = array(
         'nickname' => array('type' => 'varchar', 'length' => 64, 'description' => 'group represented'),
 
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('group_id'),
     'foreign keys' => array(
@@ -1005,7 +1006,7 @@ $schema['user_urlshortener_prefs'] = array(
         'maxnoticelength' => array('type' => 'int', 'not null' => true, 'description' => 'notices with content greater than this value will have all urls shortened, 0 = always, null = never'),
         
         'created' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was created'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('user_id'),
     'foreign keys' => array(
@@ -1018,7 +1019,7 @@ $schema['schema_version'] = array(
     'fields' => array(
         'table_name' => array('type' => 'varchar', 'length' => '64', 'not null' => true, 'description' => 'Table name'),
         'checksum' => array('type' => 'varchar', 'length' => '64', 'not null' => true, 'description' => 'Checksum of schema array; a mismatch indicates we should check the table more thoroughly.'),
-        'modified' => array('type' => 'datetime', 'not null' => true, 'description' => 'date this record was modified'),
+        'modified' => array('type' => 'timestamp', 'not null' => true, 'description' => 'date this record was modified'),
     ),
     'primary key' => array('table_name'),
 );
diff --git a/lib/mysqlschema.php b/lib/mysqlschema.php
index 937c20ea8b..153b79ccd9 100644
--- a/lib/mysqlschema.php
+++ b/lib/mysqlschema.php
@@ -117,9 +117,14 @@ class MysqlSchema extends Schema
                 $field['not null'] = true;
             }
             if ($row['COLUMN_DEFAULT'] !== null) {
-                $field['default'] = $row['COLUMN_DEFAULT'];
-                if ($this->isNumericType($type)) {
-                    $field['default'] = intval($field['default']);
+                // Hack for timestamp cols
+                if ($type == 'timestamp' && $row['COLUMN_DEFAULT'] == 'CURRENT_TIMESTAMP') {
+                    // skip
+                } else {
+                    $field['default'] = $row['COLUMN_DEFAULT'];
+                    if ($this->isNumericType($type)) {
+                        $field['default'] = intval($field['default']);
+                    }
                 }
             }
             if ($row['COLUMN_KEY'] !== null) {
@@ -251,7 +256,16 @@ class MysqlSchema extends Schema
      */
     function endCreateTable($name, array $def)
     {
-        return ") ENGINE=InnoDB CHARACTER SET utf8 COLLATE utf8_bin";
+        $engine = $this->preferredEngine($def);
+        return ") ENGINE=$engine CHARACTER SET utf8 COLLATE utf8_bin";
+    }
+    
+    function preferredEngine($def)
+    {
+        if (!empty($def['fulltext indexes'])) {
+            return 'MyISAM';
+        }
+        return 'InnoDB';
     }
 
     /**
@@ -287,14 +301,15 @@ class MysqlSchema extends Schema
      * Throw some table metadata onto the ALTER TABLE if we have a mismatch
      * in expected type, collation.
      */
-    function appendAlterExtras(array &$phrase, $tableName)
+    function appendAlterExtras(array &$phrase, $tableName, array $def)
     {
         // Check for table properties: make sure we're using a sane
         // engine type and charset/collation.
         // @fixme make the default engine configurable?
         $oldProps = $this->getTableProperties($tableName, array('ENGINE', 'TABLE_COLLATION'));
-        if (strtolower($oldProps['ENGINE']) != 'innodb') {
-            $phrase[] = 'ENGINE=InnoDB';
+        $engine = $this->preferredEngine($def);
+        if (strtolower($oldProps['ENGINE']) != strtolower($engine)) {
+            $phrase[] = "ENGINE=$engine";
         }
         if (strtolower($oldProps['TABLE_COLLATION']) != 'utf8_bin') {
             $phrase[] = 'DEFAULT CHARSET=utf8';
diff --git a/lib/schema.php b/lib/schema.php
index d62db87935..671af8a210 100644
--- a/lib/schema.php
+++ b/lib/schema.php
@@ -581,7 +581,7 @@ class Schema
             $this->appendAlterAddForeign($phrase, $keyName, $def['foreign keys'][$keyName]);
         }
 
-        $this->appendAlterExtras($phrase, $tableName);
+        $this->appendAlterExtras($phrase, $tableName, $def);
 
         if (count($phrase) > 0) {
             $sql = 'ALTER TABLE ' . $tableName . ' ' . implode(",\n", $phrase);
@@ -702,7 +702,7 @@ class Schema
         $phrase[] = 'DROP FOREIGN KEY ' . $keyName;
     }
 
-    function appendAlterExtras(array &$phrase, $tableName)
+    function appendAlterExtras(array &$phrase, $tableName, array $def)
     {
         // no-op
     }
diff --git a/lib/schemaupdater.php b/lib/schemaupdater.php
index 9577bceebf..64f7c596d4 100644
--- a/lib/schemaupdater.php
+++ b/lib/schemaupdater.php
@@ -37,7 +37,6 @@ class SchemaUpdater
     public function __construct($schema)
     {
         $this->schema = $schema;
-        $this->conn = $conn;
         $this->checksums = $this->getChecksums();
     }
 
@@ -51,13 +50,15 @@ class SchemaUpdater
     }
 
     /**
+     * Go ping em!
+     *
      * @fixme handle tables that belong on different database servers...?
      */
-    public function checkTables()
+    public function checkSchema()
     {
         $checksums = $this->checksums;
         foreach ($this->tables as $table => $def) {
-            $checksum = $this->tableChecksum($def);
+            $checksum = $this->checksum($def);
             if (empty($checksums[$table])) {
                 common_log(LOG_DEBUG, "No previous schema_version for $table: updating to $checksum");
             } else if ($checksums[$table] == $checksum) {
@@ -66,10 +67,10 @@ class SchemaUpdater
             } else {
                 common_log(LOG_DEBUG, "Last schema_version for $table is {$checksums[$table]}: updating to $checksum");
             }
-            $this->conn->query('BEGIN');
+            //$this->conn->query('BEGIN');
             $this->schema->ensureTable($table, $def);
             $this->saveChecksum($table, $checksum);
-            $this->conn->commit();
+            //$this->conn->commit();
         }
     }
 
diff --git a/scripts/checkschema.php b/scripts/checkschema.php
index bf52abe154..73fd74302c 100755
--- a/scripts/checkschema.php
+++ b/scripts/checkschema.php
@@ -27,4 +27,18 @@ END_OF_CHECKSCHEMA_HELP;
 
 require_once INSTALLDIR.'/scripts/commandline.inc';
 
+function tableDefs()
+{
+	$schema = array();
+	require INSTALLDIR.'/db/core.php';
+	return $schema;
+}
+
+$schema = Schema::get();
+$schemaUpdater = new SchemaUpdater($schema);
+foreach (tableDefs() as $table => $def) {
+	$schemaUpdater->register($table, $def);
+}
+$schemaUpdater->checkSchema();
+
 Event::handle('CheckSchema');