--
-- Create the new redirect table.
-- For each redirect, this table contains exactly one row defining its target
-- 
CREATE TABLE /*$wgDBprefix*/redirect (
  -- Key to the page_id of the redirect page
  rd_from int(8) unsigned NOT NULL default '0',

  -- Key to page_namespace/page_title of the target page.
  -- The target page may or may not exist, and due to renames
  -- and deletions may refer to different page records as time
  -- goes by.
  rd_namespace int NOT NULL default '0',
  rd_title varchar(255) binary NOT NULL default '',

  PRIMARY KEY rd_from (rd_from),
  KEY rd_ns_title (rd_namespace,rd_title,rd_from)
) TYPE=InnoDB;

-- Import existing redirects
-- Using ignore because some of the redirect pages contain more than one link
INSERT IGNORE
  INTO /*$wgDBprefix*/redirect (rd_from,rd_namespace,rd_title)
  SELECT pl_from,pl_namespace,pl_title
    FROM /*$wgDBprefix*/pagelinks, /*$wgDBprefix*/page
    WHERE pl_from=page_id AND page_is_redirect=1;