+CREATE TABLE /*_*/categorylinks_tmp (
+ -- Key to page_id of the page defined as a category member.
+ cl_from int unsigned NOT NULL default 0,
+
+ -- Name of the category.
+ -- This is also the page_title of the category's description page;
+ -- all such pages are in namespace 14 (NS_CATEGORY).
+ cl_to varchar(255) binary NOT NULL default '',
+
+ -- A binary string obtained by applying a sortkey generation algorithm
+ -- (Collation::getSortKey()) to page_title, or cl_sortkey_prefix . "\n"
+ -- . page_title if cl_sortkey_prefix is nonempty.
+ cl_sortkey varbinary(230) NOT NULL default '',
+
+ -- A prefix for the raw sortkey manually specified by the user, either via
+ -- [[Category:Foo|prefix]] or {{defaultsort:prefix}}. If nonempty, it's
+ -- concatenated with a line break followed by the page title before the sortkey
+ -- conversion algorithm is run. We store this so that we can update
+ -- collations without reparsing all pages.
+ -- Note: If you change the length of this field, you also need to change
+ -- code in LinksUpdate.php. See T27254.
+ cl_sortkey_prefix varchar(255) binary NOT NULL default '',
+
+ -- This isn't really used at present. Provided for an optional
+ -- sorting method by approximate addition time.
+ cl_timestamp timestamp NOT NULL,
+
+ -- Stores $wgCategoryCollation at the time cl_sortkey was generated. This
+ -- can be used to install new collation versions, tracking which rows are not
+ -- yet updated. '' means no collation, this is a legacy row that needs to be
+ -- updated by updateCollation.php. In the future, it might be possible to
+ -- specify different collations per category.
+ cl_collation varbinary(32) NOT NULL default '',
+
+ -- Stores whether cl_from is a category, file, or other page, so we can
+ -- paginate the three categories separately. This never has to be updated
+ -- after the page is created, since none of these page types can be moved to
+ -- any other.
+ cl_type ENUM('page', 'subcat', 'file') NOT NULL default 'page',
+ PRIMARY KEY (cl_from,cl_to)
+) /*$wgDBTableOptions*/;
+
+INSERT INTO /*_*/categorylinks_tmp
+ SELECT *
+ FROM /*_*/categorylinks;
+
+DROP TABLE /*_*/categorylinks;
+
+ALTER TABLE /*_*/categorylinks_tmp RENAME TO /*_*/categorylinks;
+
+-- We always sort within a given category, and within a given type. FIXME:
+-- Formerly this index didn't cover cl_type (since that didn't exist), so old
+-- callers won't be using an index: fix this?
+CREATE INDEX /*i*/cl_sortkey ON /*_*/categorylinks (cl_to,cl_type,cl_sortkey,cl_from);
+
+-- Used by the API (and some extensions)
+CREATE INDEX /*i*/cl_timestamp ON /*_*/categorylinks (cl_to,cl_timestamp);
+
+-- Used when updating collation (e.g. updateCollation.php)
+CREATE INDEX /*i*/cl_collation_ext ON /*_*/categorylinks (cl_collation, cl_to, cl_type, cl_from);
\ No newline at end of file