<?php
/**
 * MySQL-specific updater.
 *
 * @file
 * @ingroup Deployment
 */

/**
 * Mysql update list and mysql-specific update functions.
 *
 * @ingroup Deployment
 * @since 1.17
 */
class MysqlUpdater extends DatabaseUpdater {

	protected function getCoreUpdateList() {
		return array(
			// 1.2
			array( 'addField', 'ipblocks',      'ipb_id',           'patch-ipblocks.sql' ),
			array( 'addField', 'ipblocks',      'ipb_expiry',       'patch-ipb_expiry.sql' ),
			array( 'doInterwikiUpdate' ),
			array( 'doIndexUpdate' ),
			array( 'addTable', 'hitcounter',                        'patch-hitcounter.sql' ),
			array( 'addField', 'recentchanges', 'rc_type',          'patch-rc_type.sql' ),

			// 1.3
			array( 'addField', 'user',          'user_real_name',   'patch-user-realname.sql' ),
			array( 'addTable', 'querycache',                        'patch-querycache.sql' ),
			array( 'addTable', 'objectcache',                       'patch-objectcache.sql' ),
			array( 'addTable', 'categorylinks',                     'patch-categorylinks.sql' ),
			array( 'doOldLinksUpdate' ),
			array( 'doFixAncientImagelinks' ),
			array( 'addField', 'recentchanges', 'rc_ip',            'patch-rc_ip.sql' ),

			// 1.4
			array( 'addIndex', 'image',         'PRIMARY',          'patch-image_name_primary.sql' ),
			array( 'addField', 'recentchanges', 'rc_id',            'patch-rc_id.sql' ),
			array( 'addField', 'recentchanges', 'rc_patrolled',     'patch-rc-patrol.sql' ),
			array( 'addTable', 'logging',                           'patch-logging.sql' ),
			array( 'addField', 'user',          'user_token',       'patch-user_token.sql' ),
			array( 'addField', 'watchlist',     'wl_notificationtimestamp', 'patch-email-notification.sql' ),
			array( 'doWatchlistUpdate' ),
			array( 'dropField', 'user',         'user_emailauthenticationtimestamp', 'patch-email-authentication.sql' ),

			// 1.5
			array( 'doSchemaRestructuring' ),
			array( 'addField', 'logging',       'log_params',       'patch-log_params.sql' ),
			array( 'checkBin', 'logging',       'log_title',        'patch-logging-title.sql', ),
			array( 'addField', 'archive',       'ar_rev_id',        'patch-archive-rev_id.sql' ),
			array( 'addField', 'page',          'page_len',         'patch-page_len.sql' ),
			array( 'dropField', 'revision',     'inverse_timestamp', 'patch-inverse_timestamp.sql' ),
			array( 'addField', 'revision',      'rev_text_id',      'patch-rev_text_id.sql' ),
			array( 'addField', 'revision',      'rev_deleted',      'patch-rev_deleted.sql' ),
			array( 'addField', 'image',         'img_width',        'patch-img_width.sql' ),
			array( 'addField', 'image',         'img_metadata',     'patch-img_metadata.sql' ),
			array( 'addField', 'user',          'user_email_token', 'patch-user_email_token.sql' ),
			array( 'addField', 'archive',       'ar_text_id',       'patch-archive-text_id.sql' ),
			array( 'doNamespaceSize' ),
			array( 'addField', 'image',         'img_media_type',   'patch-img_media_type.sql' ),
			array( 'doPagelinksUpdate' ),
			array( 'dropField', 'image',        'img_type',         'patch-drop_img_type.sql' ),
			array( 'doUserUniqueUpdate' ),
			array( 'doUserGroupsUpdate' ),
			array( 'addField', 'site_stats',    'ss_total_pages',   'patch-ss_total_articles.sql' ),
			array( 'addTable', 'user_newtalk',                      'patch-usernewtalk2.sql' ),
			array( 'addTable', 'transcache',                        'patch-transcache.sql' ),
			array( 'addField', 'interwiki',     'iw_trans',         'patch-interwiki-trans.sql' ),
			array( 'addTable', 'trackbacks',                        'patch-trackbacks.sql' ),

			// 1.6
			array( 'doWatchlistNull' ),
			array( 'addIndex', 'logging',         'times',            'patch-logging-times-index.sql' ),
			array( 'addField', 'ipblocks',        'ipb_range_start',  'patch-ipb_range_start.sql' ),
			array( 'doPageRandomUpdate' ),
			array( 'addField', 'user',            'user_registration', 'patch-user_registration.sql' ),
			array( 'doTemplatelinksUpdate' ),
			array( 'addTable', 'externallinks',                       'patch-externallinks.sql' ),
			array( 'addTable', 'job',                                 'patch-job.sql' ),
			array( 'addField', 'site_stats',      'ss_images',        'patch-ss_images.sql' ),
			array( 'addTable', 'langlinks',                           'patch-langlinks.sql' ),
			array( 'addTable', 'querycache_info',                     'patch-querycacheinfo.sql' ),
			array( 'addTable', 'filearchive',                         'patch-filearchive.sql' ),
			array( 'addField', 'ipblocks',        'ipb_anon_only',    'patch-ipb_anon_only.sql' ),
			array( 'addIndex', 'recentchanges',   'rc_ns_usertext',   'patch-recentchanges-utindex.sql' ),
			array( 'addIndex', 'recentchanges',   'rc_user_text',     'patch-rc_user_text-index.sql' ),

			// 1.9
			array( 'addField', 'user',          'user_newpass_time', 'patch-user_newpass_time.sql' ),
			array( 'addTable', 'redirect',                           'patch-redirect.sql' ),
			array( 'addTable', 'querycachetwo',                      'patch-querycachetwo.sql' ),
			array( 'addField', 'ipblocks',      'ipb_enable_autoblock', 'patch-ipb_optional_autoblock.sql' ),
			array( 'doBacklinkingIndicesUpdate' ),
			array( 'addField', 'recentchanges', 'rc_old_len',        'patch-rc_len.sql' ),
			array( 'addField', 'user',          'user_editcount',    'patch-user_editcount.sql' ),

			// 1.10
			array( 'doRestrictionsUpdate' ),
			array( 'addField', 'logging',       'log_id',           'patch-log_id.sql' ),
			array( 'addField', 'revision',      'rev_parent_id',    'patch-rev_parent_id.sql' ),
			array( 'addField', 'page_restrictions', 'pr_id',        'patch-page_restrictions_sortkey.sql' ),
			array( 'addField', 'revision',      'rev_len',          'patch-rev_len.sql' ),
			array( 'addField', 'recentchanges', 'rc_deleted',       'patch-rc_deleted.sql' ),
			array( 'addField', 'logging',       'log_deleted',      'patch-log_deleted.sql' ),
			array( 'addField', 'archive',       'ar_deleted',       'patch-ar_deleted.sql' ),
			array( 'addField', 'ipblocks',      'ipb_deleted',      'patch-ipb_deleted.sql' ),
			array( 'addField', 'filearchive',   'fa_deleted',       'patch-fa_deleted.sql' ),
			array( 'addField', 'archive',       'ar_len',           'patch-ar_len.sql' ),

			// 1.11
			array( 'addField', 'ipblocks',      'ipb_block_email',  'patch-ipb_emailban.sql' ),
			array( 'doCategorylinksIndicesUpdate' ),
			array( 'addField', 'oldimage',      'oi_metadata',      'patch-oi_metadata.sql' ),
			array( 'addIndex', 'archive',       'usertext_timestamp', 'patch-archive-user-index.sql' ),
			array( 'addIndex', 'image',         'img_usertext_timestamp', 'patch-image-user-index.sql' ),
			array( 'addIndex', 'oldimage',      'oi_usertext_timestamp', 'patch-oldimage-user-index.sql' ),
			array( 'addField', 'archive',       'ar_page_id',       'patch-archive-page_id.sql' ),
			array( 'addField', 'image',         'img_sha1',         'patch-img_sha1.sql' ),

			// 1.12
			array( 'addTable', 'protected_titles',                  'patch-protected_titles.sql' ),

			// 1.13
			array( 'addField', 'ipblocks',      'ipb_by_text',      'patch-ipb_by_text.sql' ),
			array( 'addTable', 'page_props',                        'patch-page_props.sql' ),
			array( 'addTable', 'updatelog',                         'patch-updatelog.sql' ),
			array( 'addTable', 'category',                          'patch-category.sql' ),
			array( 'doCategoryPopulation' ),
			array( 'addField', 'archive',       'ar_parent_id',     'patch-ar_parent_id.sql' ),
			array( 'addField', 'user_newtalk',  'user_last_timestamp', 'patch-user_last_timestamp.sql' ),
			array( 'doPopulateParentId' ),
			array( 'checkBin', 'protected_titles', 'pt_title',      'patch-pt_title-encoding.sql', ),
			array( 'doMaybeProfilingMemoryUpdate' ),
			array( 'doFilearchiveIndicesUpdate' ),

			// 1.14
			array( 'addField', 'site_stats',    'ss_active_users',  'patch-ss_active_users.sql' ),
			array( 'doActiveUsersInit' ),
			array( 'addField', 'ipblocks',      'ipb_allow_usertalk', 'patch-ipb_allow_usertalk.sql' ),

			// 1.15
			array( 'doUniquePlTlIl' ),
			array( 'addTable', 'change_tag',                        'patch-change_tag.sql' ),
			array( 'addTable', 'tag_summary',                       'patch-change_tag.sql' ),
			array( 'addTable', 'valid_tag',                         'patch-change_tag.sql' ),

			// 1.16
			array( 'addTable', 'user_properties',                   'patch-user_properties.sql' ),
			array( 'addTable', 'log_search',                        'patch-log_search.sql' ),
			array( 'addField', 'logging',       'log_user_text',    'patch-log_user_text.sql' ),
			array( 'doLogUsertextPopulation' ), # listed separately from the previous update because 1.16 was released without this update
			array( 'doLogSearchPopulation' ),
			array( 'addTable', 'l10n_cache',                        'patch-l10n_cache.sql' ),
			array( 'addTable', 'external_user',                     'patch-external_user.sql' ),
			array( 'addIndex', 'log_search',    'ls_field_val',     'patch-log_search-rename-index.sql' ),
			array( 'addIndex', 'change_tag',    'change_tag_rc_tag', 'patch-change_tag-indexes.sql' ),
			array( 'addField', 'redirect',      'rd_interwiki',     'patch-rd_interwiki.sql' ),
			array( 'doUpdateTranscacheField' ),
			array( 'renameEuWikiId' ),
			array( 'doUpdateMimeMinorField' ),
			array( 'doPopulateRevLen' ),

			// 1.17
			array( 'addTable', 'iwlinks',                           'patch-iwlinks.sql' ),
			array( 'addIndex', 'iwlinks', 'iwl_prefix_title_from',  'patch-rename-iwl_prefix.sql' ),
			array( 'addField', 'updatelog',     'ul_value',         'patch-ul_value.sql' ),
			array( 'addField', 'interwiki',     'iw_api',           'patch-iw_api_and_wikiid.sql' ),
			array( 'dropIndex', 'iwlinks',      'iwl_prefix',       'patch-kill-iwl_prefix.sql' ),
			array( 'dropIndex', 'iwlinks',      'iwl_prefix_from_title', 'patch-kill-iwl_pft.sql' ),
			array( 'addField', 'categorylinks', 'cl_collation',     'patch-categorylinks-better-collation.sql' ),
			array( 'doClFieldsUpdate' ),
			array( 'doCollationUpdate' ),
			array( 'addTable', 'msg_resource',                      'patch-msg_resource.sql' ),
			array( 'addTable', 'module_deps',                       'patch-module_deps.sql' ),
			array( 'dropIndex', 'archive',      'ar_page_revid',    'patch-archive_kill_ar_page_revid.sql' ),
			array( 'addIndex', 'archive',       'ar_revid',         'patch-archive_ar_revid.sql' ),
			array( 'doLangLinksLengthUpdate' ),

			// 1.18
			array( 'doUserNewTalkTimestampNotNull' ),
			array( 'addIndex', 'user',          'user_email',       'patch-user_email_index.sql' ),
			array( 'modifyField', 'user_properties', 'up_property', 'patch-up_property.sql' ),
			array( 'addTable', 'uploadstash',                       'patch-uploadstash.sql' ),
			array( 'addTable', 'user_former_groups',                'patch-user_former_groups.sql'),
		);
	}

	/**
	 * 1.4 betas were missing the 'binary' marker from logging.log_title,
	 * which causes a collation mismatch error on joins in MySQL 4.1.
	 *
	 * @param $table String: table name
	 * @param $field String: field name to check
	 * @param $patchFile String: path to the patch to correct the field
	 */
	protected function checkBin( $table, $field, $patchFile ) {
		$tableName = $this->db->tableName( $table );
		$res = $this->db->query( "SELECT $field FROM $tableName LIMIT 0", __METHOD__ );
		$flags = explode( ' ', mysql_field_flags( $res->result, 0 ) );

		if ( in_array( 'binary', $flags ) ) {
			$this->output( "...$table table has correct $field encoding.\n" );
		} else {
			$this->output( "Fixing $field encoding on $table table... " );
			$this->applyPatch( $patchFile );
			$this->output( "done.\n" );
		}
	}

	/**
	 * Check whether an index contain a field
	 *
	 * @param $table String: table name
	 * @param $index String: index name to check
	 * @param $field String: field that should be in the index
	 * @return Boolean
	 */
	protected function indexHasField( $table, $index, $field ) {
		$info = $this->db->indexInfo( $table, $index, __METHOD__ );
		if ( $info ) {
			foreach ( $info as $row ) {
				if ( $row->Column_name == $field ) {
					$this->output( "...index $index on table $table includes field $field\n" );
					return true;
				}
			}
		}
		$this->output( "...index $index on table $table has no field $field; adding\n" );
		return false;
	}

	/**
	 * Check that interwiki table exists; if it doesn't source it
	 */
	protected function doInterwikiUpdate() {
		global $IP;

		if ( $this->db->tableExists( "interwiki" ) ) {
			$this->output( "...already have interwiki table\n" );
			return;
		}

		$this->output( 'Creating interwiki table...' );
		$this->applyPatch( 'patch-interwiki.sql' );
		$this->output( "ok\n" );
		$this->output( 'Adding default interwiki definitions...' );
		$this->applyPatch( "$IP/maintenance/interwiki.sql", true );
		$this->output( "done.\n" );
	}

	/**
	 * Check that proper indexes are in place
	 */
	protected function doIndexUpdate() {
		$meta = $this->db->fieldInfo( 'recentchanges', 'rc_timestamp' );
		if ( $meta === false ) {
			throw new MWException( 'Missing rc_timestamp field of recentchanges table. Should not happen.' );
		}
		if ( $meta->isMultipleKey() ) {
			$this->output( "...indexes seem up to 20031107 standards\n" );
			return;
		}

		$this->output( "Updating indexes to 20031107..." );
		$this->applyPatch( 'patch-indexes.sql', true );
		$this->output( "done.\n" );
	}

	protected function doOldLinksUpdate() {
		$cl = $this->maintenance->runChild( 'ConvertLinks' );
		$cl->execute();
	}

	protected function doFixAncientImagelinks() {
		$info = $this->db->fieldInfo( 'imagelinks', 'il_from' );
		if ( !$info || $info->type() !== 'string' ) {
			$this->output( "...il_from OK\n" );
			return;
		}

		$this->output( "Fixing ancient broken imagelinks table.\n" );
		$this->output( "NOTE: you will have to run maintenance/refreshLinks.php after this.\n" );
		$this->applyPatch( 'patch-fix-il_from.sql' );
		$this->output( "done.\n" );
	}

	/**
	 * Check if we need to add talk page rows to the watchlist
	 */
	function doWatchlistUpdate() {
		$talk = $this->db->selectField( 'watchlist', 'count(*)', 'wl_namespace & 1', __METHOD__ );
		$nontalk = $this->db->selectField( 'watchlist', 'count(*)', 'NOT (wl_namespace & 1)', __METHOD__ );
		if ( $talk == $nontalk ) {
			$this->output( "...watchlist talk page rows already present\n" );
			return;
		}

		$this->output( "Adding missing watchlist talk page rows... " );
		$this->db->insertSelect( 'watchlist', 'watchlist',
			array(
				'wl_user' => 'wl_user',
				'wl_namespace' => 'wl_namespace | 1',
				'wl_title' => 'wl_title',
				'wl_notificationtimestamp' => 'wl_notificationtimestamp'
			), array( 'NOT (wl_namespace & 1)' ), __METHOD__, 'IGNORE' );
		$this->output( "done.\n" );
	}

	function doSchemaRestructuring() {
		if ( $this->db->tableExists( 'page' ) ) {
			$this->output( "...page table already exists.\n" );
			return;
		}

		$this->output( "...converting from cur/old to page/revision/text DB structure.\n" );
		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......checking for duplicate entries.\n" );

		list ( $cur, $old, $page, $revision, $text ) = $this->db->tableNamesN( 'cur', 'old', 'page', 'revision', 'text' );

		$rows = $this->db->query( "SELECT cur_title, cur_namespace, COUNT(cur_namespace) AS c
				FROM $cur GROUP BY cur_title, cur_namespace HAVING c>1", __METHOD__ );

		if ( $rows->numRows() > 0 ) {
			$this->output( wfTimestamp( TS_DB ) );
			$this->output( "......<b>Found duplicate entries</b>\n" );
			$this->output( sprintf( "<b>      %-60s %3s %5s</b>\n", 'Title', 'NS', 'Count' ) );
			$duplicate = array();
			foreach ( $rows as $row ) {
				if ( ! isset( $duplicate[$row->cur_namespace] ) ) {
					$duplicate[$row->cur_namespace] = array();
				}
				$duplicate[$row->cur_namespace][] = $row->cur_title;
				$this->output( sprintf( "      %-60s %3s %5s\n", $row->cur_title, $row->cur_namespace, $row->c ) );
			}
			$sql = "SELECT cur_title, cur_namespace, cur_id, cur_timestamp FROM $cur WHERE ";
			$firstCond = true;
			foreach ( $duplicate as $ns => $titles ) {
				if ( $firstCond ) {
					$firstCond = false;
				} else {
					$sql .= ' OR ';
				}
				$sql .= "( cur_namespace = {$ns} AND cur_title in (";
				$first = true;
				foreach ( $titles as $t ) {
					if ( $first ) {
						$sql .= $this->db->addQuotes( $t );
						$first = false;
					} else {
						$sql .= ', ' . $this->db->addQuotes( $t );
					}
				}
				$sql .= ") ) \n";
			}
			# By sorting descending, the most recent entry will be the first in the list.
			# All following entries will be deleted by the next while-loop.
			$sql .= 'ORDER BY cur_namespace, cur_title, cur_timestamp DESC';

			$rows = $this->db->query( $sql, __METHOD__ );

			$prev_title = $prev_namespace = false;
			$deleteId = array();

			foreach ( $rows as $row ) {
				if ( $prev_title == $row->cur_title && $prev_namespace == $row->cur_namespace ) {
					$deleteId[] = $row->cur_id;
				}
				$prev_title     = $row->cur_title;
				$prev_namespace = $row->cur_namespace;
			}
			$sql = "DELETE FROM $cur WHERE cur_id IN ( " . join( ',', $deleteId ) . ')';
			$this->db->query( $sql, __METHOD__ );
			$this->output( wfTimestamp( TS_DB ) );
			$this->output( "......<b>Deleted</b> " . $this->db->affectedRows() . " records.\n" );
		}

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Creating tables.\n" );
		$this->db->query( "CREATE TABLE $page (
			page_id int(8) unsigned NOT NULL auto_increment,
			page_namespace int NOT NULL,
			page_title varchar(255) binary NOT NULL,
			page_restrictions tinyblob NOT NULL,
			page_counter bigint(20) unsigned NOT NULL default '0',
			page_is_redirect tinyint(1) unsigned NOT NULL default '0',
			page_is_new tinyint(1) unsigned NOT NULL default '0',
			page_random real unsigned NOT NULL,
			page_touched char(14) binary NOT NULL default '',
			page_latest int(8) unsigned NOT NULL,
			page_len int(8) unsigned NOT NULL,

			PRIMARY KEY page_id (page_id),
			UNIQUE INDEX name_title (page_namespace,page_title),
			INDEX (page_random),
			INDEX (page_len)
			) ENGINE=InnoDB", __METHOD__ );
		$this->db->query( "CREATE TABLE $revision (
			rev_id int(8) unsigned NOT NULL auto_increment,
			rev_page int(8) unsigned NOT NULL,
			rev_comment tinyblob NOT NULL,
			rev_user int(5) unsigned NOT NULL default '0',
			rev_user_text varchar(255) binary NOT NULL default '',
			rev_timestamp char(14) binary NOT NULL default '',
			rev_minor_edit tinyint(1) unsigned NOT NULL default '0',
			rev_deleted tinyint(1) unsigned NOT NULL default '0',
			rev_len int(8) unsigned,
			rev_parent_id int(8) unsigned default NULL,
			PRIMARY KEY rev_page_id (rev_page, rev_id),
			UNIQUE INDEX rev_id (rev_id),
			INDEX rev_timestamp (rev_timestamp),
			INDEX page_timestamp (rev_page,rev_timestamp),
			INDEX user_timestamp (rev_user,rev_timestamp),
			INDEX usertext_timestamp (rev_user_text,rev_timestamp)
			) ENGINE=InnoDB", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Locking tables.\n" );
		$this->db->query( "LOCK TABLES $page WRITE, $revision WRITE, $old WRITE, $cur WRITE", __METHOD__ );

		$maxold = intval( $this->db->selectField( 'old', 'max(old_id)', '', __METHOD__ ) );
		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......maxold is {$maxold}\n" );

		$this->output( wfTimestamp( TS_DB ) );
		global $wgLegacySchemaConversion;
		if ( $wgLegacySchemaConversion ) {
			// Create HistoryBlobCurStub entries.
			// Text will be pulled from the leftover 'cur' table at runtime.
			$this->output( "......Moving metadata from cur; using blob references to text in cur table.\n" );
			$cur_text = "concat('O:18:\"historyblobcurstub\":1:{s:6:\"mCurId\";i:',cur_id,';}')";
			$cur_flags = "'object'";
		} else {
			// Copy all cur text in immediately: this may take longer but avoids
			// having to keep an extra table around.
			$this->output( "......Moving text from cur.\n" );
			$cur_text = 'cur_text';
			$cur_flags = "''";
		}
		$this->db->query( "INSERT INTO $old (old_namespace, old_title, old_text, old_comment, old_user, old_user_text,
					old_timestamp, old_minor_edit, old_flags)
			SELECT cur_namespace, cur_title, $cur_text, cur_comment, cur_user, cur_user_text, cur_timestamp, cur_minor_edit, $cur_flags
			FROM $cur", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Setting up revision table.\n" );
		$this->db->query( "INSERT INTO $revision (rev_id, rev_page, rev_comment, rev_user, rev_user_text, rev_timestamp,
				rev_minor_edit)
			SELECT old_id, cur_id, old_comment, old_user, old_user_text,
				old_timestamp, old_minor_edit
			FROM $old,$cur WHERE old_namespace=cur_namespace AND old_title=cur_title", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Setting up page table.\n" );
		$this->db->query( "INSERT INTO $page (page_id, page_namespace, page_title, page_restrictions, page_counter,
			page_is_redirect, page_is_new, page_random, page_touched, page_latest, page_len)
			SELECT cur_id, cur_namespace, cur_title, cur_restrictions, cur_counter, cur_is_redirect, cur_is_new,
				cur_random, cur_touched, rev_id, LENGTH(cur_text)
			FROM $cur,$revision
			WHERE cur_id=rev_page AND rev_timestamp=cur_timestamp AND rev_id > {$maxold}", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Unlocking tables.\n" );
		$this->db->query( "UNLOCK TABLES", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "......Renaming old.\n" );
		$this->db->query( "ALTER TABLE $old RENAME TO $text", __METHOD__ );

		$this->output( wfTimestamp( TS_DB ) );
		$this->output( "...done.\n" );
	}

	protected function doNamespaceSize() {
		$tables = array(
			'page'          => 'page',
			'archive'       => 'ar',
			'recentchanges' => 'rc',
			'watchlist'     => 'wl',
			'querycache'    => 'qc',
			'logging'       => 'log',
		);
		foreach ( $tables as $table => $prefix ) {
			$field = $prefix . '_namespace';

			$tablename = $this->db->tableName( $table );
			$result = $this->db->query( "SHOW COLUMNS FROM $tablename LIKE '$field'", __METHOD__ );
			$info = $this->db->fetchObject( $result );

			if ( substr( $info->Type, 0, 3 ) == 'int' ) {
				$this->output( "...$field is already a full int ($info->Type).\n" );
			} else {
				$this->output( "Promoting $field from $info->Type to int... " );
				$this->db->query( "ALTER TABLE $tablename MODIFY $field int NOT NULL", __METHOD__ );
				$this->output( "done.\n" );
			}
		}
	}

	protected function doPagelinksUpdate() {
		if ( $this->db->tableExists( 'pagelinks' ) ) {
			$this->output( "...already have pagelinks table.\n" );
			return;
		}

		$this->output( "Converting links and brokenlinks tables to pagelinks... " );
		$this->applyPatch( 'patch-pagelinks.sql' );
		$this->output( "done.\n" );

		global $wgContLang;
		foreach ( MWNamespace::getCanonicalNamespaces() as $ns => $name ) {
			if ( $ns == 0 ) {
				continue;
			}

			$this->output( "Cleaning up broken links for namespace $ns... " );

			$pagelinks = $this->db->tableName( 'pagelinks' );
			$name = $wgContLang->getNsText( $ns );
			$prefix = $this->db->strencode( $name );
			$likeprefix = str_replace( '_', '\\_', $prefix );

			$sql = "UPDATE $pagelinks
					   SET pl_namespace=$ns,
						   pl_title=TRIM(LEADING '$prefix:' FROM pl_title)
					 WHERE pl_namespace=0
					   AND pl_title LIKE '$likeprefix:%'";

			$this->db->query( $sql, __METHOD__ );
			$this->output( "done.\n" );
		}
	}

	protected function doUserUniqueUpdate() {
		$duper = new UserDupes( $this->db, array( $this, 'output' ) );
		if ( $duper->hasUniqueIndex() ) {
			$this->output( "...already have unique user_name index.\n" );
			return;
		}

		if ( !$duper->clearDupes() ) {
			$this->output( "WARNING: This next step will probably fail due to unfixed duplicates...\n" );
		}
		$this->output( "Adding unique index on user_name... " );
		$this->applyPatch( 'patch-user_nameindex.sql' );
		$this->output( "done.\n" );
	}

	protected function doUserGroupsUpdate() {
		if ( $this->db->tableExists( 'user_groups' ) ) {
			$info = $this->db->fieldInfo( 'user_groups', 'ug_group' );
			if ( $info->type() == 'int' ) {
				$oldug = $this->db->tableName( 'user_groups' );
				$newug = $this->db->tableName( 'user_groups_bogus' );
				$this->output( "user_groups table exists but is in bogus intermediate format. Renaming to $newug... " );
				$this->db->query( "ALTER TABLE $oldug RENAME TO $newug", __METHOD__ );
				$this->output( "ok\n" );

				$this->output( "Re-adding fresh user_groups table... " );
				$this->applyPatch( 'patch-user_groups.sql' );
				$this->output( "ok\n" );

				$this->output( "***\n" );
				$this->output( "*** WARNING: You will need to manually fix up user permissions in the user_groups\n" );
				$this->output( "*** table. Old 1.5 alpha versions did some pretty funky stuff...\n" );
				$this->output( "***\n" );
			} else {
				$this->output( "...user_groups table exists and is in current format.\n" );
			}
			return;
		}

		$this->output( "Adding user_groups table... " );
		$this->applyPatch( 'patch-user_groups.sql' );
		$this->output( "ok\n" );

		if ( !$this->db->tableExists( 'user_rights' ) ) {
			if ( $this->db->fieldExists( 'user', 'user_rights' ) ) {
				$this->output( "Upgrading from a 1.3 or older database? Breaking out user_rights for conversion..." );
				$this->db->applyPatch( 'patch-user_rights.sql' );
				$this->output( "ok\n" );
			} else {
				$this->output( "*** WARNING: couldn't locate user_rights table or field for upgrade.\n" );
				$this->output( "*** You may need to manually configure some sysops by manipulating\n" );
				$this->output( "*** the user_groups table.\n" );
				return;
			}
		}

		$this->output( "Converting user_rights table to user_groups... " );
		$result = $this->db->select( 'user_rights',
			array( 'ur_user', 'ur_rights' ),
			array( "ur_rights != ''" ),
			__METHOD__ );

		foreach ( $result as $row ) {
			$groups = array_unique(
				array_map( 'trim',
					explode( ',', $row->ur_rights ) ) );

			foreach ( $groups as $group ) {
				$this->db->insert( 'user_groups',
					array(
						'ug_user'  => $row->ur_user,
						'ug_group' => $group ),
					__METHOD__ );
			}
		}
		$this->output( "done.\n" );
	}

	/**
	 * Make sure wl_notificationtimestamp can be NULL,
	 * and update old broken items.
	 */
	protected function doWatchlistNull() {
		$info = $this->db->fieldInfo( 'watchlist', 'wl_notificationtimestamp' );
		if ( $info->isNullable() ) {
			$this->output( "...wl_notificationtimestamp is already nullable.\n" );
			return;
		}

		$this->output( "Making wl_notificationtimestamp nullable... " );
		$this->applyPatch( 'patch-watchlist-null.sql' );
		$this->output( "done.\n" );
	}

	/**
	 * Set page_random field to a random value where it is equals to 0.
	 *
	 * @see bug 3946
	 */
	protected function doPageRandomUpdate() {
		$page = $this->db->tableName( 'page' );
		$this->db->query( "UPDATE $page SET page_random = RAND() WHERE page_random = 0", __METHOD__ );
		$rows = $this->db->affectedRows();

		if( $rows ) {
			$this->output( "Set page_random to a random value on $rows rows where it was set to 0\n" );
		} else {
			$this->output( "...no page_random rows needed to be set\n" );
		}
	}

	protected function doTemplatelinksUpdate() {
		if ( $this->db->tableExists( 'templatelinks' ) ) {
			$this->output( "...templatelinks table already exists\n" );
			return;
		}

		$this->output( "Creating templatelinks table...\n" );
		$this->applyPatch( 'patch-templatelinks.sql' );
		$this->output( "Populating...\n" );
		if ( wfGetLB()->getServerCount() > 1 ) {
			// Slow, replication-friendly update
			$res = $this->db->select( 'pagelinks', array( 'pl_from', 'pl_namespace', 'pl_title' ),
				array( 'pl_namespace' => NS_TEMPLATE ), __METHOD__ );
			$count = 0;
			foreach ( $res as $row ) {
				$count = ( $count + 1 ) % 100;
				if ( $count == 0 ) {
					wfWaitForSlaves();
				}
				$this->db->insert( 'templatelinks',
					array(
						'tl_from' => $row->pl_from,
						'tl_namespace' => $row->pl_namespace,
						'tl_title' => $row->pl_title,
					), __METHOD__
				);

			}
		} else {
			// Fast update
			$this->db->insertSelect( 'templatelinks', 'pagelinks',
				array(
					'tl_from' => 'pl_from',
					'tl_namespace' => 'pl_namespace',
					'tl_title' => 'pl_title'
				), array(
					'pl_namespace' => 10
				), __METHOD__
			);
		}
		$this->output( "Done. Please run maintenance/refreshLinks.php for a more thorough templatelinks update.\n" );
	}

	protected function doBacklinkingIndicesUpdate() {
		if ( !$this->indexHasField( 'pagelinks', 'pl_namespace', 'pl_from' ) ||
			!$this->indexHasField( 'templatelinks', 'tl_namespace', 'tl_from' ) ||
			!$this->indexHasField( 'imagelinks', 'il_to', 'il_from' ) )
		{
			$this->applyPatch( 'patch-backlinkindexes.sql' );
			$this->output( "...backlinking indices updated\n" );
		}
	}

	/**
	 * Adding page_restrictions table, obsoleting page.page_restrictions.
	 * Migrating old restrictions to new table
	 * -- Andrew Garrett, January 2007.
	 */
	protected function doRestrictionsUpdate() {
		if ( $this->db->tableExists( 'page_restrictions' ) ) {
			$this->output( "...page_restrictions table already exists.\n" );
			return;
		}

		$this->output( "Creating page_restrictions table..." );
		$this->applyPatch( 'patch-page_restrictions.sql' );
		$this->applyPatch( 'patch-page_restrictions_sortkey.sql' );
		$this->output( "done.\n" );

		$this->output( "Migrating old restrictions to new table...\n" );
		$task = $this->maintenance->runChild( 'UpdateRestrictions' );
		$task->execute();
	}

	protected function doCategorylinksIndicesUpdate() {
		if ( !$this->indexHasField( 'categorylinks', 'cl_sortkey', 'cl_from' ) ) {
			$this->applyPatch( 'patch-categorylinksindex.sql' );
			$this->output( "...categorylinks indices updated\n" );
		}
	}

	protected function doCategoryPopulation() {
		if ( $this->updateRowExists( 'populate category' ) ) {
			$this->output( "...category table already populated.\n" );
			return;
		}

		$this->output(
			"Populating category table, printing progress markers. " .
			"For large databases, you\n" .
			"may want to hit Ctrl-C and do this manually with maintenance/\n" .
			"populateCategory.php.\n"
		);
		$task = $this->maintenance->runChild( 'PopulateCategory' );
		$task->execute();
		$this->output( "Done populating category table.\n" );
	}

	protected function doPopulateParentId() {
		if ( $this->updateRowExists( 'populate rev_parent_id' ) ) {
			$this->output( "...rev_parent_id column already populated.\n" );
			return;
		}

		$task = $this->maintenance->runChild( 'PopulateParentId' );
		$task->execute();
	}

	protected function doMaybeProfilingMemoryUpdate() {
		if ( !$this->db->tableExists( 'profiling' ) ) {
			// Simply ignore
		} elseif ( $this->db->fieldExists( 'profiling', 'pf_memory' ) ) {
			$this->output( "...profiling table has pf_memory field.\n" );
		} else {
			$this->output( "Adding pf_memory field to table profiling..." );
			$this->applyPatch( 'patch-profiling-memory.sql' );
			$this->output( "done.\n" );
		}
	}

	protected function doFilearchiveIndicesUpdate() {
		$info = $this->db->indexInfo( 'filearchive', 'fa_user_timestamp', __METHOD__ );
		if ( !$info ) {
			$this->output( "Updating filearchive indices..." );
			$this->applyPatch( 'patch-filearchive-user-index.sql' );
			$this->output( "done.\n" );
		}
	}

	protected function doUniquePlTlIl() {
		$info = $this->db->indexInfo( 'pagelinks', 'pl_namespace' );
		if ( is_array( $info ) && !$info[0]->Non_unique ) {
			$this->output( "...pl_namespace, tl_namespace, il_to indices are already UNIQUE.\n" );
			return;
		}

		$this->output( "Making pl_namespace, tl_namespace and il_to indices UNIQUE... " );
		$this->applyPatch( 'patch-pl-tl-il-unique.sql' );
		$this->output( "done.\n" );
	}

	protected function renameEuWikiId() {
		if ( $this->db->fieldExists( 'external_user', 'eu_local_id' ) ) {
			$this->output( "...eu_wiki_id already renamed to eu_local_id.\n" );
			return;
		}

		$this->output( "Renaming eu_wiki_id -> eu_local_id... " );
		$this->applyPatch( 'patch-eu_local_id.sql' );
		$this->output( "done.\n" );
	}

	protected function doUpdateMimeMinorField() {
		if ( $this->updateRowExists( 'mime_minor_length' ) ) {
			$this->output( "...*_mime_minor fields are already long enough.\n" );
			return;
		}

		$this->output( "Altering all *_mime_minor fields to 100 bytes in size ... " );
		$this->applyPatch( 'patch-mime_minor_length.sql' );
		$this->output( "done.\n" );
	}

	protected function doPopulateRevLen() {
		if ( $this->updateRowExists( 'populate rev_len' ) ) {
			$this->output( "...rev_len column already populated.\n" );
			return;
		}

		$task = $this->maintenance->runChild( 'PopulateRevisionLength' );
		$task->execute();
	}

	protected function doClFieldsUpdate() {
		if ( $this->updateRowExists( 'cl_fields_update' ) ) {
			$this->output( "...categorylinks up-to-date.\n" );
			return;
		}

		$this->output( 'Updating categorylinks (again)...' );
		$this->applyPatch( 'patch-categorylinks-better-collation2.sql' );
		$this->output( "done.\n" );
	}

	protected function doLangLinksLengthUpdate() {
		$langlinks = $this->db->tableName( 'langlinks' );
		$res = $this->db->query( "SHOW COLUMNS FROM $langlinks LIKE 'll_lang'" );
		$row = $this->db->fetchObject( $res );

		if ( $row && $row->Type == "varbinary(10)" ) {
			$this->output( 'Updating length of ll_lang in langlinks...' );
			$this->applyPatch( 'patch-langlinks-ll_lang-20.sql' );
			$this->output( "done.\n" );
		} else {
			$this->output( "...ll_lang is up-to-date.\n" );
		}
	}

	protected function doUserNewTalkTimestampNotNull() {
		$info = $this->db->fieldInfo( 'user_newtalk', 'user_last_timestamp' );
		if ( $info->isNullable() ) {
			$this->output( "...user_last_timestamp is already nullable.\n" );
			return;
		}

		$this->output( "Making user_last_timestamp nullable... " );
		$this->applyPatch( 'patch-user-newtalk-timestamp-null.sql' );
		$this->output( "done.\n" );
	}
}