text: -- SQL to create the initial tables for the MediaWiki database.
  -- This is read and executed by the install script; you should
  -- not have to run it by itself unless doing a manual install.
  
  -- This is a shared schema file used for both MySQL and SQLite installs.
  --
  -- For more documentation on the database schema, see
  -- https://www.mediawiki.org/wiki/Manual:Database_layout
  --
  -- General notes:
  --
  -- If possible, create tables as InnoDB to benefit from the
  -- superior resiliency against crashes and ability to read
  -- during writes (and write during reads!)
  --
  -- Only the 'searchindex' table requires MyISAM due to the
  -- requirement for fulltext index support, which is missing
  -- from InnoDB.
  --
  --
  -- The MySQL table backend for MediaWiki currently uses
  -- 14-character BINARY or VARBINARY fields to store timestamps.
  -- The format is YYYYMMDDHHMMSS, which is derived from the
  -- text format of MySQL's TIMESTAMP fields.
  --
  -- Historically TIMESTAMP fields were used, but abandoned
  -- in early 2002 after a lot of trouble with the fields
  -- auto-updating.
  --
  -- The Postgres backend uses TIMESTAMPTZ fields for timestamps,
  -- and we will migrate the MySQL definitions at some point as
  -- well.
  --
  --
  -- The /*_*/ comments in this and other files are
  -- replaced with the defined table prefix by the installer
  -- and updater scripts. If you are installing or running
  -- updates manually, you will need to manually insert the
  -- table prefix if any when running these scripts.
  --
  
  
  --
  -- The user table contains basic account information,
  -- authentication keys, etc.
  --
  -- Some multi-wiki sites may share a single central user table
  -- between separate wikis using the $wgSharedDB setting.
  --
  -- Note that when a external authentication plugin is used,
  -- user table entries still need to be created to store
  -- preferences and to key tracking information in the other
  -- tables.
  --
  CREATE TABLE /*_*/user (
    user_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Usernames must be unique, must not be in the form of
    -- an IP address. _Shouldn't_ allow slashes or case
    -- conflicts. Spaces are allowed, and are _not_ converted
    -- to underscores like titles. See the User::newFromName() for
    -- the specific tests that usernames have to pass.
    user_name varchar(255) binary NOT NULL default '',
  
    -- Optional 'real name' to be displayed in credit listings
    user_real_name varchar(255) binary NOT NULL default '',
  
    -- Password hashes, see User::crypt() and User::comparePasswords()
    -- in User.php for the algorithm
    user_password tinyblob NOT NULL,
  
    -- When using 'mail me a new password', a random
    -- password is generated and the hash stored here.
    -- The previous password is left in place until
    -- someone actually logs in with the new password,
    -- at which point the hash is moved to user_password
    -- and the old password is invalidated.
    user_newpassword tinyblob NOT NULL,
  
    -- Timestamp of the last time when a new password was
    -- sent, for throttling and expiring purposes
    -- Emailed passwords will expire $wgNewPasswordExpiry
    -- (a week) after being set. If user_newpass_time is NULL
    -- (eg. created by mail) it doesn't expire.
    user_newpass_time binary(14),
  
    -- Note: email should be restricted, not public info.
    -- Same with passwords.
    user_email tinytext NOT NULL,
  
    -- If the browser sends an If-Modified-Since header, a 304 response is
    -- suppressed if the value in this field for the current user is later than
    -- the value in the IMS header. That is, this field is an invalidation timestamp
    -- for the browser cache of logged-in users. Among other things, it is used
    -- to prevent pages generated for a previously logged in user from being
    -- displayed after a session expiry followed by a fresh login.
    user_touched binary(14) NOT NULL default '',
  
    -- A pseudorandomly generated value that is stored in
    -- a cookie when the "remember password" feature is
    -- used (previously, a hash of the password was used, but
    -- this was vulnerable to cookie-stealing attacks)
    user_token binary(32) NOT NULL default '',
  
    -- Initially NULL; when a user's e-mail address has been
    -- validated by returning with a mailed token, this is
    -- set to the current timestamp.
    user_email_authenticated binary(14),
  
    -- Randomly generated token created when the e-mail address
    -- is set and a confirmation test mail sent.
    user_email_token binary(32),
  
    -- Expiration date for the user_email_token
    user_email_token_expires binary(14),
  
    -- Timestamp of account registration.
    -- Accounts predating this schema addition may contain NULL.
    user_registration binary(14),
  
    -- Count of edits and edit-like actions.
    --
    -- *NOT* intended to be an accurate copy of COUNT(*) WHERE rev_user=user_id
    -- May contain NULL for old accounts if batch-update scripts haven't been
    -- run, as well as listing deleted edits and other myriad ways it could be
    -- out of sync.
    --
    -- Meant primarily for heuristic checks to give an impression of whether
    -- the account has been used much.
    --
    user_editcount int,
  
    -- Expiration date for user password.
    user_password_expires varbinary(14) DEFAULT NULL
  
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/user_name ON /*_*/user (user_name);
  CREATE INDEX /*i*/user_email_token ON /*_*/user (user_email_token);
  CREATE INDEX /*i*/user_email ON /*_*/user (user_email(50));
  
  
  --
  -- User permissions have been broken out to a separate table;
  -- this allows sites with a shared user table to have different
  -- permissions assigned to a user in each project.
  --
  -- This table replaces the old user_rights field which used a
  -- comma-separated blob.
  --
  CREATE TABLE /*_*/user_groups (
    -- Key to user_id
    ug_user int unsigned NOT NULL default 0,
  
    -- Group names are short symbolic string keys.
    -- The set of group names is open-ended, though in practice
    -- only some predefined ones are likely to be used.
    --
    -- At runtime $wgGroupPermissions will associate group keys
    -- with particular permissions. A user will have the combined
    -- permissions of any group they're explicitly in, plus
    -- the implicit '*' and 'user' groups.
    ug_group varbinary(255) NOT NULL default '',
  
    -- Time at which the user group membership will expire. Set to
    -- NULL for a non-expiring (infinite) membership.
    ug_expiry varbinary(14) NULL default NULL,
  
    PRIMARY KEY (ug_user, ug_group)
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/ug_group ON /*_*/user_groups (ug_group);
  CREATE INDEX /*i*/ug_expiry ON /*_*/user_groups (ug_expiry);
  
  -- Stores the groups the user has once belonged to.
  -- The user may still belong to these groups (check user_groups).
  -- Users are not autopromoted to groups from which they were removed.
  CREATE TABLE /*_*/user_former_groups (
    -- Key to user_id
    ufg_user int unsigned NOT NULL default 0,
    ufg_group varbinary(255) NOT NULL default '',
    PRIMARY KEY (ufg_user,ufg_group)
  ) /*$wgDBTableOptions*/;
  
  --
  -- Stores notifications of user talk page changes, for the display
  -- of the "you have new messages" box
  --
  CREATE TABLE /*_*/user_newtalk (
    -- Key to user.user_id
    user_id int unsigned NOT NULL default 0,
    -- If the user is an anonymous user their IP address is stored here
    -- since the user_id of 0 is ambiguous
    user_ip varbinary(40) NOT NULL default '',
    -- The highest timestamp of revisions of the talk page viewed
    -- by this user
    user_last_timestamp varbinary(14) NULL default NULL
  ) /*$wgDBTableOptions*/;
  
  -- Indexes renamed for SQLite in 1.14
  CREATE INDEX /*i*/un_user_id ON /*_*/user_newtalk (user_id);
  CREATE INDEX /*i*/un_user_ip ON /*_*/user_newtalk (user_ip);
  
  
  --
  -- User preferences and perhaps other fun stuff. :)
  -- Replaces the old user.user_options blob, with a couple nice properties:
  --
  -- 1) We only store non-default settings, so changes to the defauls
  --    are now reflected for everybody, not just new accounts.
  -- 2) We can more easily do bulk lookups, statistics, or modifications of
  --    saved options since it's a sane table structure.
  --
  CREATE TABLE /*_*/user_properties (
    -- Foreign key to user.user_id
    up_user int unsigned NOT NULL,
  
    -- Name of the option being saved. This is indexed for bulk lookup.
    up_property varbinary(255) NOT NULL,
  
    -- Property value as a string.
    up_value blob,
    PRIMARY KEY (up_user,up_property)
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/user_properties_property ON /*_*/user_properties (up_property);
  
  --
  -- This table contains a user's bot passwords: passwords that allow access to
  -- the account via the API with limited rights.
  --
  CREATE TABLE /*_*/bot_passwords (
    -- User ID obtained from CentralIdLookup.
    bp_user int unsigned NOT NULL,
  
    -- Application identifier
    bp_app_id varbinary(32) NOT NULL,
  
    -- Password hashes, like user.user_password
    bp_password tinyblob NOT NULL,
  
    -- Like user.user_token
    bp_token binary(32) NOT NULL default '',
  
    -- JSON blob for MWRestrictions
    bp_restrictions blob NOT NULL,
  
    -- Grants allowed to the account when authenticated with this bot-password
    bp_grants blob NOT NULL,
  
    PRIMARY KEY ( bp_user, bp_app_id )
  ) /*$wgDBTableOptions*/;
  
  --
  -- Core of the wiki: each page has an entry here which identifies
  -- it by title and contains some essential metadata.
  --
  CREATE TABLE /*_*/page (
    -- Unique identifier number. The page_id will be preserved across
    -- edits and rename operations, but not deletions and recreations.
    page_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- A page name is broken into a namespace and a title.
    -- The namespace keys are UI-language-independent constants,
    -- defined in includes/Defines.php
    page_namespace int NOT NULL,
  
    -- The rest of the title, as text.
    -- Spaces are transformed into underscores in title storage.
    page_title varchar(255) binary NOT NULL,
  
    -- Comma-separated set of permission keys indicating who
    -- can move or edit the page.
    page_restrictions tinyblob NOT NULL,
  
    -- 1 indicates the article is a redirect.
    page_is_redirect tinyint unsigned NOT NULL default 0,
  
    -- 1 indicates this is a new entry, with only one edit.
    -- Not all pages with one edit are new pages.
    page_is_new tinyint unsigned NOT NULL default 0,
  
    -- Random value between 0 and 1, used for Special:Randompage
    page_random real unsigned NOT NULL,
  
    -- This timestamp is updated whenever the page changes in
    -- a way requiring it to be re-rendered, invalidating caches.
    -- Aside from editing this includes permission changes,
    -- creation or deletion of linked pages, and alteration
    -- of contained templates.
    page_touched binary(14) NOT NULL default '',
  
    -- This timestamp is updated whenever a page is re-parsed and
    -- it has all the link tracking tables updated for it. This is
    -- useful for de-duplicating expensive backlink update jobs.
    page_links_updated varbinary(14) NULL default NULL,
  
    -- Handy key to revision.rev_id of the current revision.
    -- This may be 0 during page creation, but that shouldn't
    -- happen outside of a transaction... hopefully.
    page_latest int unsigned NOT NULL,
  
    -- Uncompressed length in bytes of the page's current source text.
    page_len int unsigned NOT NULL,
  
    -- content model, see CONTENT_MODEL_XXX constants
    page_content_model varbinary(32) DEFAULT NULL,
  
    -- Page content language
    page_lang varbinary(35) DEFAULT NULL
  ) /*$wgDBTableOptions*/;
  
  -- The title index. Care must be taken to always specify a namespace when
  -- by title, so that the index is used. Even listing all known namespaces
  -- with IN() is better than omitting page_namespace from the WHERE clause.
  CREATE UNIQUE INDEX /*i*/name_title ON /*_*/page (page_namespace,page_title);
  
  -- The index for Special:Random
  CREATE INDEX /*i*/page_random ON /*_*/page (page_random);
  
  -- Questionable utility, used by ProofreadPage, possibly DynamicPageList.
  -- ApiQueryAllPages unconditionally filters on namespace and so hopefully does
  -- not use it.
  CREATE INDEX /*i*/page_len ON /*_*/page (page_len);
  
  -- The index for Special:Shortpages and Special:Longpages. Also SiteStats::articles()
  -- in 'comma' counting mode, MessageCache::loadFromDB().
  CREATE INDEX /*i*/page_redirect_namespace_len ON /*_*/page (page_is_redirect, page_namespace, page_len);
  
  --
  -- Every edit of a page creates also a revision row.
  -- This stores metadata about the revision, and a reference
  -- to the text storage backend.
  --
  CREATE TABLE /*_*/revision (
    -- Unique ID to identify each revision
    rev_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Key to page_id. This should _never_ be invalid.
    rev_page int unsigned NOT NULL,
  
    -- Key to text.old_id, where the actual bulk text is stored.
    -- It's possible for multiple revisions to use the same text,
    -- for instance revisions where only metadata is altered
    -- or a rollback to a previous version.
    rev_text_id int unsigned NOT NULL,
  
    -- Text comment summarizing the change. Deprecated in favor of
    -- revision_comment_temp.revcomment_comment_id.
    rev_comment varbinary(767) NOT NULL default '',
  
    -- Key to user.user_id of the user who made this edit.
    -- Stores 0 for anonymous edits and for some mass imports.
    rev_user int unsigned NOT NULL default 0,
  
    -- Text username or IP address of the editor.
    rev_user_text varchar(255) binary NOT NULL default '',
  
    -- Timestamp of when revision was created
    rev_timestamp binary(14) NOT NULL default '',
  
    -- Records whether the user marked the 'minor edit' checkbox.
    -- Many automated edits are marked as minor.
    rev_minor_edit tinyint unsigned NOT NULL default 0,
  
    -- Restrictions on who can access this revision
    rev_deleted tinyint unsigned NOT NULL default 0,
  
    -- Length of this revision in bytes
    rev_len int unsigned,
  
    -- Key to revision.rev_id
    -- This field is used to add support for a tree structure (The Adjacency List Model)
    rev_parent_id int unsigned default NULL,
  
    -- SHA-1 text content hash in base-36
    rev_sha1 varbinary(32) NOT NULL default '',
  
    -- content model, see CONTENT_MODEL_XXX constants
    rev_content_model varbinary(32) DEFAULT NULL,
  
    -- content format, see CONTENT_FORMAT_XXX constants
    rev_content_format varbinary(64) DEFAULT NULL
  
  ) /*$wgDBTableOptions*/ MAX_ROWS=10000000 AVG_ROW_LENGTH=1024;
  -- In case tables are created as MyISAM, use row hints for MySQL <5.0 to avoid 4GB limit
  
  -- The index is proposed for removal, do not use it in new code: T163532.
  -- Used for ordering revisions within a page by rev_id, which is usually
  -- incorrect, since rev_timestamp is normally the correct order. It can also
  -- be used by dumpBackup.php, if a page and rev_id range is specified.
  CREATE INDEX /*i*/rev_page_id ON /*_*/revision (rev_page, rev_id);
  
  -- Used by ApiQueryAllRevisions
  CREATE INDEX /*i*/rev_timestamp ON /*_*/revision (rev_timestamp);
  
  -- History index
  CREATE INDEX /*i*/page_timestamp ON /*_*/revision (rev_page,rev_timestamp);
  
  -- Logged-in user contributions index
  CREATE INDEX /*i*/user_timestamp ON /*_*/revision (rev_user,rev_timestamp);
  
  -- Anonymous user countributions index
  CREATE INDEX /*i*/usertext_timestamp ON /*_*/revision (rev_user_text,rev_timestamp);
  
  -- Credits index. This is scanned in order to compile credits lists for pages,
  -- in ApiQueryContributors. Also for ApiQueryRevisions if rvuser is specified
  -- and is a logged-in user.
  CREATE INDEX /*i*/page_user_timestamp ON /*_*/revision (rev_page,rev_user,rev_timestamp);
  
  --
  -- Temporary table to avoid blocking on an alter of revision.
  --
  -- On large wikis like the English Wikipedia, altering the revision table is a
  -- months-long process. This table is being created to avoid such an alter, and
  -- will be merged back into revision in the future.
  --
  CREATE TABLE /*_*/revision_comment_temp (
    -- Key to rev_id
    revcomment_rev int unsigned NOT NULL,
    -- Key to comment_id
    revcomment_comment_id bigint unsigned NOT NULL,
    PRIMARY KEY (revcomment_rev, revcomment_comment_id)
  ) /*$wgDBTableOptions*/;
  -- Ensure uniqueness
  CREATE UNIQUE INDEX /*i*/revcomment_rev ON /*_*/revision_comment_temp (revcomment_rev);
  
  --
  -- Every time an edit by a logged out user is saved,
  -- a row is created in ip_changes. This stores
  -- the IP as a hex representation so that we can more
  -- easily find edits within an IP range.
  --
  CREATE TABLE /*_*/ip_changes (
    -- Foreign key to the revision table, also serves as the unique primary key
    ipc_rev_id int unsigned NOT NULL PRIMARY KEY DEFAULT '0',
  
    -- The timestamp of the revision
    ipc_rev_timestamp binary(14) NOT NULL DEFAULT '',
  
    -- Hex representation of the IP address, as returned by IP::toHex()
    -- For IPv4 it will resemble: ABCD1234
    -- For IPv6: v6-ABCD1234000000000000000000000000
    -- BETWEEN is then used to identify revisions within a given range
    ipc_hex varbinary(35) NOT NULL DEFAULT ''
  
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/ipc_rev_timestamp ON /*_*/ip_changes (ipc_rev_timestamp);
  CREATE INDEX /*i*/ipc_hex_time ON /*_*/ip_changes (ipc_hex,ipc_rev_timestamp);
  
  --
  -- Holds text of individual page revisions.
  --
  -- Field names are a holdover from the 'old' revisions table in
  -- MediaWiki 1.4 and earlier: an upgrade will transform that
  -- table into the 'text' table to minimize unnecessary churning
  -- and downtime. If upgrading, the other fields will be left unused.
  --
  CREATE TABLE /*_*/text (
    -- Unique text storage key number.
    -- Note that the 'oldid' parameter used in URLs does *not*
    -- refer to this number anymore, but to rev_id.
    --
    -- revision.rev_text_id is a key to this column
    old_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Depending on the contents of the old_flags field, the text
    -- may be convenient plain text, or it may be funkily encoded.
    old_text mediumblob NOT NULL,
  
    -- Comma-separated list of flags:
    -- gzip: text is compressed with PHP's gzdeflate() function.
    -- utf-8: text was stored as UTF-8.
    --        If $wgLegacyEncoding option is on, rows *without* this flag
    --        will be converted to UTF-8 transparently at load time. Note
    --        that due to a bug in a maintenance script, this flag may
    --        have been stored as 'utf8' in some cases (T18841).
    -- object: text field contained a serialized PHP object.
    --         The object either contains multiple versions compressed
    --         together to achieve a better compression ratio, or it refers
    --         to another row where the text can be found.
    -- external: text was stored in an external location specified by old_text.
    --           Any additional flags apply to the data stored at that URL, not
    --           the URL itself. The 'object' flag is *not* set for URLs of the
    --           form 'DB://cluster/id/itemid', because the external storage
    --           system itself decompresses these.
    old_flags tinyblob NOT NULL
  ) /*$wgDBTableOptions*/ MAX_ROWS=10000000 AVG_ROW_LENGTH=10240;
  -- In case tables are created as MyISAM, use row hints for MySQL <5.0 to avoid 4GB limit
  
  
  --
  -- Edits, blocks, and other actions typically have a textual comment describing
  -- the action. They are stored here to reduce the size of the main tables, and
  -- to allow for deduplication.
  --
  -- Deduplication is currently best-effort to avoid locking on inserts that
  -- would be required for strict deduplication. There MAY be multiple rows with
  -- the same comment_text and comment_data.
  --
  CREATE TABLE /*_*/comment (
    -- Unique ID to identify each comment
    comment_id bigint unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Hash of comment_text and comment_data, for deduplication
    comment_hash INT NOT NULL,
  
    -- Text comment summarizing the change.
    -- This text is shown in the history and other changes lists,
    -- rendered in a subset of wiki markup by Linker::formatComment()
    -- Size limits are enforced at the application level, and should
    -- take care to crop UTF-8 strings appropriately.
    comment_text BLOB NOT NULL,
  
    -- JSON data, intended for localizing auto-generated comments.
    -- This holds structured data that is intended to be used to provide
    -- localized versions of automatically-generated comments. When not empty,
    -- comment_text should be the generated comment localized using the wiki's
    -- content language.
    comment_data BLOB
  ) /*$wgDBTableOptions*/;
  -- Index used for deduplication.
  CREATE INDEX /*i*/comment_hash ON /*_*/comment (comment_hash);
  
  
  --
  -- Holding area for deleted articles, which may be viewed
  -- or restored by admins through the Special:Undelete interface.
  -- The fields generally correspond to the page, revision, and text
  -- fields, with several caveats.
  --
  CREATE TABLE /*_*/archive (
    -- Primary key
    ar_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
    ar_namespace int NOT NULL default 0,
    ar_title varchar(255) binary NOT NULL default '',
  
    -- Newly deleted pages will not store text in this table,
    -- but will reference the separately existing text rows.
    -- This field is retained for backwards compatibility,
    -- so old archived pages will remain accessible after
    -- upgrading from 1.4 to 1.5.
    -- Text may be gzipped or otherwise funky.
    ar_text mediumblob NOT NULL,
  
    -- Basic revision stuff...
    ar_comment varbinary(767) NOT NULL default '', -- Deprecated in favor of ar_comment_id
    ar_comment_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that ar_comment should be used)
    ar_user int unsigned NOT NULL default 0,
    ar_user_text varchar(255) binary NOT NULL,
    ar_timestamp binary(14) NOT NULL default '',
    ar_minor_edit tinyint NOT NULL default 0,
  
    -- See ar_text note.
    ar_flags tinyblob NOT NULL,
  
    -- When revisions are deleted, their unique rev_id is stored
    -- here so it can be retained after undeletion. This is necessary
    -- to retain permalinks to given revisions after accidental delete
    -- cycles or messy operations like history merges.
    --
    -- Old entries from 1.4 will be NULL here, and a new rev_id will
    -- be created on undeletion for those revisions.
    ar_rev_id int unsigned,
  
    -- For newly deleted revisions, this is the text.old_id key to the
    -- actual stored text. To avoid breaking the block-compression scheme
    -- and otherwise making storage changes harder, the actual text is
    -- *not* deleted from the text table, merely hidden by removal of the
    -- page and revision entries.
    --
    -- Old entries deleted under 1.2-1.4 will have NULL here, and their
    -- ar_text and ar_flags fields will be used to create a new text
    -- row upon undeletion.
    ar_text_id int unsigned,
  
    -- rev_deleted for archives
    ar_deleted tinyint unsigned NOT NULL default 0,
  
    -- Length of this revision in bytes
    ar_len int unsigned,
  
    -- Reference to page_id. Useful for sysadmin fixing of large pages
    -- merged together in the archives, or for cleanly restoring a page
    -- at its original ID number if possible.
    --
    -- Will be NULL for pages deleted prior to 1.11.
    ar_page_id int unsigned,
  
    -- Original previous revision
    ar_parent_id int unsigned default NULL,
  
    -- SHA-1 text content hash in base-36
    ar_sha1 varbinary(32) NOT NULL default '',
  
    -- content model, see CONTENT_MODEL_XXX constants
    ar_content_model varbinary(32) DEFAULT NULL,
  
    -- content format, see CONTENT_FORMAT_XXX constants
    ar_content_format varbinary(64) DEFAULT NULL
  ) /*$wgDBTableOptions*/;
  
  -- Index for Special:Undelete to page through deleted revisions
  CREATE INDEX /*i*/name_title_timestamp ON /*_*/archive (ar_namespace,ar_title,ar_timestamp);
  
  -- Index for Special:DeletedContributions
  CREATE INDEX /*i*/ar_usertext_timestamp ON /*_*/archive (ar_user_text,ar_timestamp);
  
  -- Index for linking archive rows with tables that normally link with revision
  -- rows, such as change_tag.
  CREATE INDEX /*i*/ar_revid ON /*_*/archive (ar_rev_id);
  
  
  --
  -- Track page-to-page hyperlinks within the wiki.
  --
  CREATE TABLE /*_*/pagelinks (
    -- Key to the page_id of the page containing the link.
    pl_from int unsigned NOT NULL default 0,
    -- Namespace for this page
    pl_from_namespace int 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.
    pl_namespace int NOT NULL default 0,
    pl_title varchar(255) binary NOT NULL default '',
    PRIMARY KEY (pl_from,pl_namespace,pl_title)
  ) /*$wgDBTableOptions*/;
  
  -- Reverse index, for Special:Whatlinkshere
  CREATE INDEX /*i*/pl_namespace ON /*_*/pagelinks (pl_namespace,pl_title,pl_from);
  
  -- Index for Special:Whatlinkshere with namespace filter
  CREATE INDEX /*i*/pl_backlinks_namespace ON /*_*/pagelinks (pl_from_namespace,pl_namespace,pl_title,pl_from);
  
  
  --
  -- Track template inclusions.
  --
  CREATE TABLE /*_*/templatelinks (
    -- Key to the page_id of the page containing the link.
    tl_from int unsigned NOT NULL default 0,
    -- Namespace for this page
    tl_from_namespace int 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.
    tl_namespace int NOT NULL default 0,
    tl_title varchar(255) binary NOT NULL default '',
    PRIMARY KEY (tl_from,tl_namespace,tl_title)
  ) /*$wgDBTableOptions*/;
  
  -- Reverse index, for Special:Whatlinkshere
  CREATE INDEX /*i*/tl_namespace ON /*_*/templatelinks (tl_namespace,tl_title,tl_from);
  
  -- Index for Special:Whatlinkshere with namespace filter
  CREATE INDEX /*i*/tl_backlinks_namespace ON /*_*/templatelinks (tl_from_namespace,tl_namespace,tl_title,tl_from);
  
  
  --
  -- Track links to images *used inline*
  -- We don't distinguish live from broken links here, so
  -- they do not need to be changed on upload/removal.
  --
  CREATE TABLE /*_*/imagelinks (
    -- Key to page_id of the page containing the image / media link.
    il_from int unsigned NOT NULL default 0,
    -- Namespace for this page
    il_from_namespace int NOT NULL default 0,
  
    -- Filename of target image.
    -- This is also the page_title of the file's description page;
    -- all such pages are in namespace 6 (NS_FILE).
    il_to varchar(255) binary NOT NULL default '',
    PRIMARY KEY (il_from,il_to)
  ) /*$wgDBTableOptions*/;
  
  -- Reverse index, for Special:Whatlinkshere and file description page local usage
  CREATE INDEX /*i*/il_to ON /*_*/imagelinks (il_to,il_from);
  
  -- Index for Special:Whatlinkshere with namespace filter
  CREATE INDEX /*i*/il_backlinks_namespace ON /*_*/imagelinks (il_from_namespace,il_to,il_from);
  
  
  --
  -- Track category inclusions *used inline*
  -- This tracks a single level of category membership
  --
  CREATE TABLE /*_*/categorylinks (
    -- 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*/;
  
  
  -- 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);
  
  --
  -- Track all existing categories. Something is a category if 1) it has an entry
  -- somewhere in categorylinks, or 2) it has a description page. Categories
  -- might not have corresponding pages, so they need to be tracked separately.
  --
  CREATE TABLE /*_*/category (
    -- Primary key
    cat_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Name of the category, in the same form as page_title (with underscores).
    -- If there is a category page corresponding to this category, by definition,
    -- it has this name (in the Category namespace).
    cat_title varchar(255) binary NOT NULL,
  
    -- The numbers of member pages (including categories and media), subcatego-
    -- ries, and Image: namespace members, respectively.  These are signed to
    -- make underflow more obvious.  We make the first number include the second
    -- two for better sorting: subtracting for display is easy, adding for order-
    -- ing is not.
    cat_pages int signed NOT NULL default 0,
    cat_subcats int signed NOT NULL default 0,
    cat_files int signed NOT NULL default 0
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/cat_title ON /*_*/category (cat_title);
  
  -- For Special:Mostlinkedcategories
  CREATE INDEX /*i*/cat_pages ON /*_*/category (cat_pages);
  
  
  --
  -- Track links to external URLs
  --
  CREATE TABLE /*_*/externallinks (
    -- Primary key
    el_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- page_id of the referring page
    el_from int unsigned NOT NULL default 0,
  
    -- The URL
    el_to blob NOT NULL,
  
    -- In the case of HTTP URLs, this is the URL with any username or password
    -- removed, and with the labels in the hostname reversed and converted to
    -- lower case. An extra dot is added to allow for matching of either
    -- example.com or *.example.com in a single scan.
    -- Example:
    --      http://user:password@sub.example.com/page.html
    --   becomes
    --      http://com.example.sub./page.html
    -- which allows for fast searching for all pages under example.com with the
    -- clause:
    --      WHERE el_index LIKE 'http://com.example.%'
    el_index blob NOT NULL,
  
    -- This is el_index truncated to 60 bytes to allow for sortable queries that
    -- aren't supported by a partial index.
    -- @todo Drop the default once this is deployed everywhere and code is populating it.
    el_index_60 varbinary(60) NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  -- Forward index, for page edit, save
  CREATE INDEX /*i*/el_from ON /*_*/externallinks (el_from, el_to(40));
  
  -- Index for Special:LinkSearch exact search
  CREATE INDEX /*i*/el_to ON /*_*/externallinks (el_to(60), el_from);
  
  -- For Special:LinkSearch wildcard search
  CREATE INDEX /*i*/el_index ON /*_*/externallinks (el_index(60));
  
  -- For Special:LinkSearch wildcard search with efficient paging by el_id
  CREATE INDEX /*i*/el_index_60 ON /*_*/externallinks (el_index_60, el_id);
  CREATE INDEX /*i*/el_from_index_60 ON /*_*/externallinks (el_from, el_index_60, el_id);
  
  --
  -- Track interlanguage links
  --
  CREATE TABLE /*_*/langlinks (
    -- page_id of the referring page
    ll_from int unsigned NOT NULL default 0,
  
    -- Language code of the target
    ll_lang varbinary(20) NOT NULL default '',
  
    -- Title of the target, including namespace
    ll_title varchar(255) binary NOT NULL default '',
    PRIMARY KEY (ll_from,ll_lang)
  ) /*$wgDBTableOptions*/;
  
  -- Index for ApiQueryLangbacklinks
  CREATE INDEX /*i*/ll_lang ON /*_*/langlinks (ll_lang, ll_title);
  
  
  --
  -- Track inline interwiki links
  --
  CREATE TABLE /*_*/iwlinks (
    -- page_id of the referring page
    iwl_from int unsigned NOT NULL default 0,
  
    -- Interwiki prefix code of the target
    iwl_prefix varbinary(20) NOT NULL default '',
  
    -- Title of the target, including namespace
    iwl_title varchar(255) binary NOT NULL default '',
    PRIMARY KEY (iwl_from,iwl_prefix,iwl_title)
  ) /*$wgDBTableOptions*/;
  
  -- Index for ApiQueryIWBacklinks
  CREATE INDEX /*i*/iwl_prefix_title_from ON /*_*/iwlinks (iwl_prefix, iwl_title, iwl_from);
  
  -- Index for ApiQueryIWLinks
  CREATE INDEX /*i*/iwl_prefix_from_title ON /*_*/iwlinks (iwl_prefix, iwl_from, iwl_title);
  
  
  --
  -- Contains a single row with some aggregate info
  -- on the state of the site.
  --
  CREATE TABLE /*_*/site_stats (
    -- The single row should contain 1 here.
    ss_row_id int unsigned NOT NULL PRIMARY KEY,
  
    -- Total number of edits performed.
    ss_total_edits bigint unsigned default 0,
  
    -- An approximate count of pages matching the following criteria:
    -- * in namespace 0
    -- * not a redirect
    -- * contains the text '[['
    -- See Article::isCountable() in includes/Article.php
    ss_good_articles bigint unsigned default 0,
  
    -- Total pages, theoretically equal to SELECT COUNT(*) FROM page; except faster
    ss_total_pages bigint default '-1',
  
    -- Number of users, theoretically equal to SELECT COUNT(*) FROM user;
    ss_users bigint default '-1',
  
    -- Number of users that still edit
    ss_active_users bigint default '-1',
  
    -- Number of images, equivalent to SELECT COUNT(*) FROM image
    ss_images int default 0
  ) /*$wgDBTableOptions*/;
  
  --
  -- The internet is full of jerks, alas. Sometimes it's handy
  -- to block a vandal or troll account.
  --
  CREATE TABLE /*_*/ipblocks (
    -- Primary key, introduced for privacy.
    ipb_id int NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Blocked IP address in dotted-quad form or user name.
    ipb_address tinyblob NOT NULL,
  
    -- Blocked user ID or 0 for IP blocks.
    ipb_user int unsigned NOT NULL default 0,
  
    -- User ID who made the block.
    ipb_by int unsigned NOT NULL default 0,
  
    -- User name of blocker
    ipb_by_text varchar(255) binary NOT NULL default '',
  
    -- Text comment made by blocker. Deprecated in favor of ipb_reason_id
    ipb_reason varbinary(767) NOT NULL default '',
  
    -- Key to comment_id. Text comment made by blocker.
    -- ("DEFAULT 0" is temporary, signaling that ipb_reason should be used)
    ipb_reason_id bigint unsigned NOT NULL DEFAULT 0,
  
    -- Creation (or refresh) date in standard YMDHMS form.
    -- IP blocks expire automatically.
    ipb_timestamp binary(14) NOT NULL default '',
  
    -- Indicates that the IP address was banned because a banned
    -- user accessed a page through it. If this is 1, ipb_address
    -- will be hidden, and the block identified by block ID number.
    ipb_auto bool NOT NULL default 0,
  
    -- If set to 1, block applies only to logged-out users
    ipb_anon_only bool NOT NULL default 0,
  
    -- Block prevents account creation from matching IP addresses
    ipb_create_account bool NOT NULL default 1,
  
    -- Block triggers autoblocks
    ipb_enable_autoblock bool NOT NULL default '1',
  
    -- Time at which the block will expire.
    -- May be "infinity"
    ipb_expiry varbinary(14) NOT NULL default '',
  
    -- Start and end of an address range, in hexadecimal
    -- Size chosen to allow IPv6
    -- FIXME: these fields were originally blank for single-IP blocks,
    -- but now they are populated. No migration was ever done. They
    -- should be fixed to be blank again for such blocks (T51504).
    ipb_range_start tinyblob NOT NULL,
    ipb_range_end tinyblob NOT NULL,
  
    -- Flag for entries hidden from users and Sysops
    ipb_deleted bool NOT NULL default 0,
  
    -- Block prevents user from accessing Special:Emailuser
    ipb_block_email bool NOT NULL default 0,
  
    -- Block allows user to edit their own talk page
    ipb_allow_usertalk bool NOT NULL default 0,
  
    -- ID of the block that caused this block to exist
    -- Autoblocks set this to the original block
    -- so that the original block being deleted also
    -- deletes the autoblocks
    ipb_parent_block_id int default NULL
  
  ) /*$wgDBTableOptions*/;
  
  -- Unique index to support "user already blocked" messages
  -- Any new options which prevent collisions should be included
  CREATE UNIQUE INDEX /*i*/ipb_address ON /*_*/ipblocks (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only);
  
  -- For querying whether a logged-in user is blocked
  CREATE INDEX /*i*/ipb_user ON /*_*/ipblocks (ipb_user);
  
  -- For querying whether an IP address is in any range
  CREATE INDEX /*i*/ipb_range ON /*_*/ipblocks (ipb_range_start(8), ipb_range_end(8));
  
  -- Index for Special:BlockList
  CREATE INDEX /*i*/ipb_timestamp ON /*_*/ipblocks (ipb_timestamp);
  
  -- Index for table pruning
  CREATE INDEX /*i*/ipb_expiry ON /*_*/ipblocks (ipb_expiry);
  
  -- Index for removing autoblocks when a parent block is removed
  CREATE INDEX /*i*/ipb_parent_block_id ON /*_*/ipblocks (ipb_parent_block_id);
  
  
  --
  -- Uploaded images and other files.
  --
  CREATE TABLE /*_*/image (
    -- Filename.
    -- This is also the title of the associated description page,
    -- which will be in namespace 6 (NS_FILE).
    img_name varchar(255) binary NOT NULL default '' PRIMARY KEY,
  
    -- File size in bytes.
    img_size int unsigned NOT NULL default 0,
  
    -- For images, size in pixels.
    img_width int NOT NULL default 0,
    img_height int NOT NULL default 0,
  
    -- Extracted Exif metadata stored as a serialized PHP array.
    img_metadata mediumblob NOT NULL,
  
    -- For images, bits per pixel if known.
    img_bits int NOT NULL default 0,
  
    -- Media type as defined by the MEDIATYPE_xxx constants
    img_media_type ENUM("UNKNOWN", "BITMAP", "DRAWING", "AUDIO", "VIDEO", "MULTIMEDIA", "OFFICE", "TEXT", "EXECUTABLE", "ARCHIVE", "3D") default NULL,
  
    -- major part of a MIME media type as defined by IANA
    -- see https://www.iana.org/assignments/media-types/
    -- for "chemical" cf. http://dx.doi.org/10.1021/ci9803233 by the ACS
    img_major_mime ENUM("unknown", "application", "audio", "image", "text", "video", "message", "model", "multipart", "chemical") NOT NULL default "unknown",
  
    -- minor part of a MIME media type as defined by IANA
    -- the minor parts are not required to adher to any standard
    -- but should be consistent throughout the database
    -- see https://www.iana.org/assignments/media-types/
    img_minor_mime varbinary(100) NOT NULL default "unknown",
  
    -- Description field as entered by the uploader.
    -- This is displayed in image upload history and logs.
    -- Deprecated in favor of image_comment_temp.imgcomment_description_id.
    img_description varbinary(767) NOT NULL default '',
  
    -- user_id and user_name of uploader.
    img_user int unsigned NOT NULL default 0,
    img_user_text varchar(255) binary NOT NULL,
  
    -- Time of the upload.
    img_timestamp varbinary(14) NOT NULL default '',
  
    -- SHA-1 content hash in base-36
    img_sha1 varbinary(32) NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  -- Used by Special:Newimages and ApiQueryAllImages
  CREATE INDEX /*i*/img_user_timestamp ON /*_*/image (img_user,img_timestamp);
  CREATE INDEX /*i*/img_usertext_timestamp ON /*_*/image (img_user_text,img_timestamp);
  -- Used by Special:ListFiles for sort-by-size
  CREATE INDEX /*i*/img_size ON /*_*/image (img_size);
  -- Used by Special:Newimages and Special:ListFiles
  CREATE INDEX /*i*/img_timestamp ON /*_*/image (img_timestamp);
  -- Used in API and duplicate search
  CREATE INDEX /*i*/img_sha1 ON /*_*/image (img_sha1(10));
  -- Used to get media of one type
  CREATE INDEX /*i*/img_media_mime ON /*_*/image (img_media_type,img_major_mime,img_minor_mime);
  
  --
  -- Temporary table to avoid blocking on an alter of image.
  --
  -- On large wikis like Wikimedia Commons, altering the image table is a
  -- months-long process. This table is being created to avoid such an alter, and
  -- will be merged back into image in the future.
  --
  CREATE TABLE /*_*/image_comment_temp (
    -- Key to img_name (ugh)
    imgcomment_name varchar(255) binary NOT NULL,
    -- Key to comment_id
    imgcomment_description_id bigint unsigned NOT NULL,
    PRIMARY KEY (imgcomment_name, imgcomment_description_id)
  ) /*$wgDBTableOptions*/;
  -- Ensure uniqueness
  CREATE UNIQUE INDEX /*i*/imgcomment_name ON /*_*/image_comment_temp (imgcomment_name);
  
  
  --
  -- Previous revisions of uploaded files.
  -- Awkwardly, image rows have to be moved into
  -- this table at re-upload time.
  --
  CREATE TABLE /*_*/oldimage (
    -- Base filename: key to image.img_name
    oi_name varchar(255) binary NOT NULL default '',
  
    -- Filename of the archived file.
    -- This is generally a timestamp and '!' prepended to the base name.
    oi_archive_name varchar(255) binary NOT NULL default '',
  
    -- Other fields as in image...
    oi_size int unsigned NOT NULL default 0,
    oi_width int NOT NULL default 0,
    oi_height int NOT NULL default 0,
    oi_bits int NOT NULL default 0,
    oi_description varbinary(767) NOT NULL default '', -- Deprecated.
    oi_description_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that oi_description should be used)
    oi_user int unsigned NOT NULL default 0,
    oi_user_text varchar(255) binary NOT NULL,
    oi_timestamp binary(14) NOT NULL default '',
  
    oi_metadata mediumblob NOT NULL,
    oi_media_type ENUM("UNKNOWN", "BITMAP", "DRAWING", "AUDIO", "VIDEO", "MULTIMEDIA", "OFFICE", "TEXT", "EXECUTABLE", "ARCHIVE", "3D") default NULL,
    oi_major_mime ENUM("unknown", "application", "audio", "image", "text", "video", "message", "model", "multipart", "chemical") NOT NULL default "unknown",
    oi_minor_mime varbinary(100) NOT NULL default "unknown",
    oi_deleted tinyint unsigned NOT NULL default 0,
    oi_sha1 varbinary(32) NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/oi_usertext_timestamp ON /*_*/oldimage (oi_user_text,oi_timestamp);
  CREATE INDEX /*i*/oi_name_timestamp ON /*_*/oldimage (oi_name,oi_timestamp);
  -- oi_archive_name truncated to 14 to avoid key length overflow
  CREATE INDEX /*i*/oi_name_archive_name ON /*_*/oldimage (oi_name,oi_archive_name(14));
  CREATE INDEX /*i*/oi_sha1 ON /*_*/oldimage (oi_sha1(10));
  
  
  --
  -- Record of deleted file data
  --
  CREATE TABLE /*_*/filearchive (
    -- Unique row id
    fa_id int NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Original base filename; key to image.img_name, page.page_title, etc
    fa_name varchar(255) binary NOT NULL default '',
  
    -- Filename of archived file, if an old revision
    fa_archive_name varchar(255) binary default '',
  
    -- Which storage bin (directory tree or object store) the file data
    -- is stored in. Should be 'deleted' for files that have been deleted;
    -- any other bin is not yet in use.
    fa_storage_group varbinary(16),
  
    -- SHA-1 of the file contents plus extension, used as a key for storage.
    -- eg 8f8a562add37052a1848ff7771a2c515db94baa9.jpg
    --
    -- If NULL, the file was missing at deletion time or has been purged
    -- from the archival storage.
    fa_storage_key varbinary(64) default '',
  
    -- Deletion information, if this file is deleted.
    fa_deleted_user int,
    fa_deleted_timestamp binary(14) default '',
    fa_deleted_reason varbinary(767) default '', -- Deprecated
    fa_deleted_reason_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that fa_deleted_reason should be used)
  
    -- Duped fields from image
    fa_size int unsigned default 0,
    fa_width int default 0,
    fa_height int default 0,
    fa_metadata mediumblob,
    fa_bits int default 0,
    fa_media_type ENUM("UNKNOWN", "BITMAP", "DRAWING", "AUDIO", "VIDEO", "MULTIMEDIA", "OFFICE", "TEXT", "EXECUTABLE", "ARCHIVE", "3D") default NULL,
    fa_major_mime ENUM("unknown", "application", "audio", "image", "text", "video", "message", "model", "multipart", "chemical") default "unknown",
    fa_minor_mime varbinary(100) default "unknown",
    fa_description varbinary(767) default '', -- Deprecated
    fa_description_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that fa_description should be used)
    fa_user int unsigned default 0,
    fa_user_text varchar(255) binary,
    fa_timestamp binary(14) default '',
  
    -- Visibility of deleted revisions, bitfield
    fa_deleted tinyint unsigned NOT NULL default 0,
  
    -- sha1 hash of file content
    fa_sha1 varbinary(32) NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  -- pick out by image name
  CREATE INDEX /*i*/fa_name ON /*_*/filearchive (fa_name, fa_timestamp);
  -- pick out dupe files
  CREATE INDEX /*i*/fa_storage_group ON /*_*/filearchive (fa_storage_group, fa_storage_key);
  -- sort by deletion time
  CREATE INDEX /*i*/fa_deleted_timestamp ON /*_*/filearchive (fa_deleted_timestamp);
  -- sort by uploader
  CREATE INDEX /*i*/fa_user_timestamp ON /*_*/filearchive (fa_user_text,fa_timestamp);
  -- find file by sha1, 10 bytes will be enough for hashes to be indexed
  CREATE INDEX /*i*/fa_sha1 ON /*_*/filearchive (fa_sha1(10));
  
  
  --
  -- Store information about newly uploaded files before they're
  -- moved into the actual filestore
  --
  CREATE TABLE /*_*/uploadstash (
    us_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- the user who uploaded the file.
    us_user int unsigned NOT NULL,
  
    -- file key. this is how applications actually search for the file.
    -- this might go away, or become the primary key.
    us_key varchar(255) NOT NULL,
  
    -- the original path
    us_orig_path varchar(255) NOT NULL,
  
    -- the temporary path at which the file is actually stored
    us_path varchar(255) NOT NULL,
  
    -- which type of upload the file came from (sometimes)
    us_source_type varchar(50),
  
    -- the date/time on which the file was added
    us_timestamp varbinary(14) NOT NULL,
  
    us_status varchar(50) NOT NULL,
  
    -- chunk counter starts at 0, current offset is stored in us_size
    us_chunk_inx int unsigned NULL,
  
    -- Serialized file properties from FSFile::getProps()
    us_props blob,
  
    -- file size in bytes
    us_size int unsigned NOT NULL,
    -- this hash comes from FSFile::getSha1Base36(), and is 31 characters
    us_sha1 varchar(31) NOT NULL,
    us_mime varchar(255),
    -- Media type as defined by the MEDIATYPE_xxx constants, should duplicate definition in the image table
    us_media_type ENUM("UNKNOWN", "BITMAP", "DRAWING", "AUDIO", "VIDEO", "MULTIMEDIA", "OFFICE", "TEXT", "EXECUTABLE", "ARCHIVE", "3D") default NULL,
    -- image-specific properties
    us_image_width int unsigned,
    us_image_height int unsigned,
    us_image_bits smallint unsigned
  
  ) /*$wgDBTableOptions*/;
  
  -- sometimes there's a delete for all of a user's stuff.
  CREATE INDEX /*i*/us_user ON /*_*/uploadstash (us_user);
  -- pick out files by key, enforce key uniqueness
  CREATE UNIQUE INDEX /*i*/us_key ON /*_*/uploadstash (us_key);
  -- the abandoned upload cleanup script needs this
  CREATE INDEX /*i*/us_timestamp ON /*_*/uploadstash (us_timestamp);
  
  
  --
  -- Primarily a summary table for Special:Recentchanges,
  -- this table contains some additional info on edits from
  -- the last few days, see Article::editUpdates()
  --
  CREATE TABLE /*_*/recentchanges (
    rc_id int NOT NULL PRIMARY KEY AUTO_INCREMENT,
    rc_timestamp varbinary(14) NOT NULL default '',
  
    -- As in revision
    rc_user int unsigned NOT NULL default 0,
    rc_user_text varchar(255) binary NOT NULL,
  
    -- When pages are renamed, their RC entries do _not_ change.
    rc_namespace int NOT NULL default 0,
    rc_title varchar(255) binary NOT NULL default '',
  
    -- as in revision...
    rc_comment varbinary(767) NOT NULL default '', -- Deprecated.
    rc_comment_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that rc_comment should be used)
    rc_minor tinyint unsigned NOT NULL default 0,
  
    -- Edits by user accounts with the 'bot' rights key are
    -- marked with a 1 here, and will be hidden from the
    -- default view.
    rc_bot tinyint unsigned NOT NULL default 0,
  
    -- Set if this change corresponds to a page creation
    rc_new tinyint unsigned NOT NULL default 0,
  
    -- Key to page_id (was cur_id prior to 1.5).
    -- This will keep links working after moves while
    -- retaining the at-the-time name in the changes list.
    rc_cur_id int unsigned NOT NULL default 0,
  
    -- rev_id of the given revision
    rc_this_oldid int unsigned NOT NULL default 0,
  
    -- rev_id of the prior revision, for generating diff links.
    rc_last_oldid int unsigned NOT NULL default 0,
  
    -- The type of change entry (RC_EDIT,RC_NEW,RC_LOG,RC_EXTERNAL)
    rc_type tinyint unsigned NOT NULL default 0,
  
    -- The source of the change entry (replaces rc_type)
    -- default of '' is temporary, needed for initial migration
    rc_source varchar(16) binary not null default '',
  
    -- If the Recent Changes Patrol option is enabled,
    -- users may mark edits as having been reviewed to
    -- remove a warning flag on the RC list.
    -- A value of 1 indicates the page has been reviewed.
    rc_patrolled tinyint unsigned NOT NULL default 0,
  
    -- Recorded IP address the edit was made from, if the
    -- $wgPutIPinRC option is enabled.
    rc_ip varbinary(40) NOT NULL default '',
  
    -- Text length in characters before
    -- and after the edit
    rc_old_len int,
    rc_new_len int,
  
    -- Visibility of recent changes items, bitfield
    rc_deleted tinyint unsigned NOT NULL default 0,
  
    -- Value corresponding to log_id, specific log entries
    rc_logid int unsigned NOT NULL default 0,
    -- Store log type info here, or null
    rc_log_type varbinary(255) NULL default NULL,
    -- Store log action or null
    rc_log_action varbinary(255) NULL default NULL,
    -- Log params
    rc_params blob NULL
  ) /*$wgDBTableOptions*/;
  
  -- Special:Recentchanges
  CREATE INDEX /*i*/rc_timestamp ON /*_*/recentchanges (rc_timestamp);
  
  -- Special:Watchlist
  CREATE INDEX /*i*/rc_namespace_title ON /*_*/recentchanges (rc_namespace, rc_title);
  
  -- Special:Recentchangeslinked when finding changes in pages linked from a page
  CREATE INDEX /*i*/rc_cur_id ON /*_*/recentchanges (rc_cur_id);
  
  -- Special:Newpages
  CREATE INDEX /*i*/new_name_timestamp ON /*_*/recentchanges (rc_new,rc_namespace,rc_timestamp);
  
  -- Blank unless $wgPutIPinRC=true (false at WMF), possibly used by extensions,
  -- but mostly replaced by CheckUser.
  CREATE INDEX /*i*/rc_ip ON /*_*/recentchanges (rc_ip);
  
  -- Probably intended for Special:NewPages namespace filter
  CREATE INDEX /*i*/rc_ns_usertext ON /*_*/recentchanges (rc_namespace, rc_user_text);
  
  -- SiteStats active user count, Special:ActiveUsers, Special:NewPages user filter
  CREATE INDEX /*i*/rc_user_text ON /*_*/recentchanges (rc_user_text, rc_timestamp);
  
  -- ApiQueryRecentChanges (T140108)
  CREATE INDEX /*i*/rc_name_type_patrolled_timestamp ON /*_*/recentchanges (rc_namespace, rc_type, rc_patrolled, rc_timestamp);
  
  
  CREATE TABLE /*_*/watchlist (
    wl_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
    -- Key to user.user_id
    wl_user int unsigned NOT NULL,
  
    -- Key to page_namespace/page_title
    -- Note that users may watch pages which do not exist yet,
    -- or existed in the past but have been deleted.
    wl_namespace int NOT NULL default 0,
    wl_title varchar(255) binary NOT NULL default '',
  
    -- Timestamp used to send notification e-mails and show "updated since last visit" markers on
    -- history and recent changes / watchlist. Set to NULL when the user visits the latest revision
    -- of the page, which means that they should be sent an e-mail on the next change.
    wl_notificationtimestamp varbinary(14)
  
  ) /*$wgDBTableOptions*/;
  
  -- Special:Watchlist
  CREATE UNIQUE INDEX /*i*/wl_user ON /*_*/watchlist (wl_user, wl_namespace, wl_title);
  
  -- Special:Movepage (WatchedItemStore::duplicateEntry)
  CREATE INDEX /*i*/namespace_title ON /*_*/watchlist (wl_namespace, wl_title);
  
  -- ApiQueryWatchlistRaw changed filter
  CREATE INDEX /*i*/wl_user_notificationtimestamp ON /*_*/watchlist (wl_user, wl_notificationtimestamp);
  
  
  --
  -- When using the default MySQL search backend, page titles
  -- and text are munged to strip markup, do Unicode case folding,
  -- and prepare the result for MySQL's fulltext index.
  --
  -- This table must be MyISAM; InnoDB does not support the needed
  -- fulltext index.
  --
  CREATE TABLE /*_*/searchindex (
    -- Key to page_id
    si_page int unsigned NOT NULL,
  
    -- Munged version of title
    si_title varchar(255) NOT NULL default '',
  
    -- Munged version of body text
    si_text mediumtext NOT NULL
  ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
  
  CREATE UNIQUE INDEX /*i*/si_page ON /*_*/searchindex (si_page);
  CREATE FULLTEXT INDEX /*i*/si_title ON /*_*/searchindex (si_title);
  CREATE FULLTEXT INDEX /*i*/si_text ON /*_*/searchindex (si_text);
  
  
  --
  -- Recognized interwiki link prefixes
  --
  CREATE TABLE /*_*/interwiki (
    -- The interwiki prefix, (e.g. "Meatball", or the language prefix "de")
    iw_prefix varchar(32) NOT NULL,
  
    -- The URL of the wiki, with "$1" as a placeholder for an article name.
    -- Any spaces in the name will be transformed to underscores before
    -- insertion.
    iw_url blob NOT NULL,
  
    -- The URL of the file api.php
    iw_api blob NOT NULL,
  
    -- The name of the database (for a connection to be established with wfGetLB( 'wikiid' ))
    iw_wikiid varchar(64) NOT NULL,
  
    -- A boolean value indicating whether the wiki is in this project
    -- (used, for example, to detect redirect loops)
    iw_local bool NOT NULL,
  
    -- Boolean value indicating whether interwiki transclusions are allowed.
    iw_trans tinyint NOT NULL default 0
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/iw_prefix ON /*_*/interwiki (iw_prefix);
  
  
  --
  -- Used for caching expensive grouped queries
  --
  CREATE TABLE /*_*/querycache (
    -- A key name, generally the base name of of the special page.
    qc_type varbinary(32) NOT NULL,
  
    -- Some sort of stored value. Sizes, counts...
    qc_value int unsigned NOT NULL default 0,
  
    -- Target namespace+title
    qc_namespace int NOT NULL default 0,
    qc_title varchar(255) binary NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/qc_type ON /*_*/querycache (qc_type,qc_value);
  
  
  --
  -- For a few generic cache operations if not using Memcached
  --
  CREATE TABLE /*_*/objectcache (
    keyname varbinary(255) NOT NULL default '' PRIMARY KEY,
    value mediumblob,
    exptime datetime
  ) /*$wgDBTableOptions*/;
  CREATE INDEX /*i*/exptime ON /*_*/objectcache (exptime);
  
  
  --
  -- Cache of interwiki transclusion
  --
  CREATE TABLE /*_*/transcache (
    tc_url varbinary(255) NOT NULL PRIMARY KEY,
    tc_contents text,
    tc_time binary(14) NOT NULL
  ) /*$wgDBTableOptions*/;
  
  
  CREATE TABLE /*_*/logging (
    -- Log ID, for referring to this specific log entry, probably for deletion and such.
    log_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Symbolic keys for the general log type and the action type
    -- within the log. The output format will be controlled by the
    -- action field, but only the type controls categorization.
    log_type varbinary(32) NOT NULL default '',
    log_action varbinary(32) NOT NULL default '',
  
    -- Timestamp. Duh.
    log_timestamp binary(14) NOT NULL default '19700101000000',
  
    -- The user who performed this action; key to user_id
    log_user int unsigned NOT NULL default 0,
  
    -- Name of the user who performed this action
    log_user_text varchar(255) binary NOT NULL default '',
  
    -- Key to the page affected. Where a user is the target,
    -- this will point to the user page.
    log_namespace int NOT NULL default 0,
    log_title varchar(255) binary NOT NULL default '',
    log_page int unsigned NULL,
  
    -- Freeform text. Interpreted as edit history comments.
    -- Deprecated in favor of log_comment_id.
    log_comment varbinary(767) NOT NULL default '',
  
    -- Key to comment_id. Comment summarizing the change.
    -- ("DEFAULT 0" is temporary, signaling that log_comment should be used)
    log_comment_id bigint unsigned NOT NULL DEFAULT 0,
  
    -- miscellaneous parameters:
    -- LF separated list (old system) or serialized PHP array (new system)
    log_params blob NOT NULL,
  
    -- rev_deleted for logs
    log_deleted tinyint unsigned NOT NULL default 0
  ) /*$wgDBTableOptions*/;
  
  -- Special:Log type filter
  CREATE INDEX /*i*/type_time ON /*_*/logging (log_type, log_timestamp);
  
  -- Special:Log performer filter
  CREATE INDEX /*i*/user_time ON /*_*/logging (log_user, log_timestamp);
  
  -- Special:Log title filter, log extract
  CREATE INDEX /*i*/page_time ON /*_*/logging (log_namespace, log_title, log_timestamp);
  
  -- Special:Log unfiltered
  CREATE INDEX /*i*/times ON /*_*/logging (log_timestamp);
  
  -- Special:Log filter by performer and type
  CREATE INDEX /*i*/log_user_type_time ON /*_*/logging (log_user, log_type, log_timestamp);
  
  -- Apparently just used for a few maintenance pages (findMissingFiles.php, Flow).
  -- Could be removed?
  CREATE INDEX /*i*/log_page_id_time ON /*_*/logging (log_page,log_timestamp);
  
  -- Special:Log action filter
  CREATE INDEX /*i*/type_action ON /*_*/logging (log_type, log_action, log_timestamp);
  
  -- Special:Log filter by type and anonymous performer
  CREATE INDEX /*i*/log_user_text_type_time ON /*_*/logging (log_user_text, log_type, log_timestamp);
  
  -- Special:Log filter by anonymous performer
  CREATE INDEX /*i*/log_user_text_time ON /*_*/logging (log_user_text, log_timestamp);
  
  
  CREATE TABLE /*_*/log_search (
    -- The type of ID (rev ID, log ID, rev timestamp, username)
    ls_field varbinary(32) NOT NULL,
    -- The value of the ID
    ls_value varchar(255) NOT NULL,
    -- Key to log_id
    ls_log_id int unsigned NOT NULL default 0,
    PRIMARY KEY (ls_field,ls_value,ls_log_id)
  ) /*$wgDBTableOptions*/;
  CREATE INDEX /*i*/ls_log_id ON /*_*/log_search (ls_log_id);
  
  
  -- Jobs performed by parallel apache threads or a command-line daemon
  CREATE TABLE /*_*/job (
    job_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Command name
    -- Limited to 60 to prevent key length overflow
    job_cmd varbinary(60) NOT NULL default '',
  
    -- Namespace and title to act on
    -- Should be 0 and '' if the command does not operate on a title
    job_namespace int NOT NULL,
    job_title varchar(255) binary NOT NULL,
  
    -- Timestamp of when the job was inserted
    -- NULL for jobs added before addition of the timestamp
    job_timestamp varbinary(14) NULL default NULL,
  
    -- Any other parameters to the command
    -- Stored as a PHP serialized array, or an empty string if there are no parameters
    job_params blob NOT NULL,
  
    -- Random, non-unique, number used for job acquisition (for lock concurrency)
    job_random integer unsigned NOT NULL default 0,
  
    -- The number of times this job has been locked
    job_attempts integer unsigned NOT NULL default 0,
  
    -- Field that conveys process locks on rows via process UUIDs
    job_token varbinary(32) NOT NULL default '',
  
    -- Timestamp when the job was locked
    job_token_timestamp varbinary(14) NULL default NULL,
  
    -- Base 36 SHA1 of the job parameters relevant to detecting duplicates
    job_sha1 varbinary(32) NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/job_sha1 ON /*_*/job (job_sha1);
  CREATE INDEX /*i*/job_cmd_token ON /*_*/job (job_cmd,job_token,job_random);
  CREATE INDEX /*i*/job_cmd_token_id ON /*_*/job (job_cmd,job_token,job_id);
  CREATE INDEX /*i*/job_cmd ON /*_*/job (job_cmd, job_namespace, job_title, job_params(128));
  CREATE INDEX /*i*/job_timestamp ON /*_*/job (job_timestamp);
  
  
  -- Details of updates to cached special pages
  CREATE TABLE /*_*/querycache_info (
    -- Special page name
    -- Corresponds to a qc_type value
    qci_type varbinary(32) NOT NULL default '' PRIMARY KEY,
  
    -- Timestamp of last update
    qci_timestamp binary(14) NOT NULL default '19700101000000'
  ) /*$wgDBTableOptions*/;
  
  
  -- For each redirect, this table contains exactly one row defining its target
  CREATE TABLE /*_*/redirect (
    -- Key to the page_id of the redirect page
    rd_from int unsigned NOT NULL default 0 PRIMARY KEY,
  
    -- 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 '',
    rd_interwiki varchar(32) default NULL,
    rd_fragment varchar(255) binary default NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/rd_ns_title ON /*_*/redirect (rd_namespace,rd_title,rd_from);
  
  
  -- Used for caching expensive grouped queries that need two links (for example double-redirects)
  CREATE TABLE /*_*/querycachetwo (
    -- A key name, generally the base name of of the special page.
    qcc_type varbinary(32) NOT NULL,
  
    -- Some sort of stored value. Sizes, counts...
    qcc_value int unsigned NOT NULL default 0,
  
    -- Target namespace+title
    qcc_namespace int NOT NULL default 0,
    qcc_title varchar(255) binary NOT NULL default '',
  
    -- Target namespace+title2
    qcc_namespacetwo int NOT NULL default 0,
    qcc_titletwo varchar(255) binary NOT NULL default ''
  ) /*$wgDBTableOptions*/;
  
  CREATE INDEX /*i*/qcc_type ON /*_*/querycachetwo (qcc_type,qcc_value);
  CREATE INDEX /*i*/qcc_title ON /*_*/querycachetwo (qcc_type,qcc_namespace,qcc_title);
  CREATE INDEX /*i*/qcc_titletwo ON /*_*/querycachetwo (qcc_type,qcc_namespacetwo,qcc_titletwo);
  
  
  -- Used for storing page restrictions (i.e. protection levels)
  CREATE TABLE /*_*/page_restrictions (
    -- Field for an ID for this restrictions row (sort-key for Special:ProtectedPages)
    pr_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
    -- Page to apply restrictions to (Foreign Key to page).
    pr_page int NOT NULL,
    -- The protection type (edit, move, etc)
    pr_type varbinary(60) NOT NULL,
    -- The protection level (Sysop, autoconfirmed, etc)
    pr_level varbinary(60) NOT NULL,
    -- Whether or not to cascade the protection down to pages transcluded.
    pr_cascade tinyint NOT NULL,
    -- Field for future support of per-user restriction.
    pr_user int unsigned NULL,
    -- Field for time-limited protection.
    pr_expiry varbinary(14) NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/pr_pagetype ON /*_*/page_restrictions (pr_page,pr_type);
  CREATE INDEX /*i*/pr_typelevel ON /*_*/page_restrictions (pr_type,pr_level);
  CREATE INDEX /*i*/pr_level ON /*_*/page_restrictions (pr_level);
  CREATE INDEX /*i*/pr_cascade ON /*_*/page_restrictions (pr_cascade);
  
  
  -- Protected titles - nonexistent pages that have been protected
  CREATE TABLE /*_*/protected_titles (
    pt_namespace int NOT NULL,
    pt_title varchar(255) binary NOT NULL,
    pt_user int unsigned NOT NULL,
    pt_reason varbinary(767) default '', -- Deprecated.
    pt_reason_id bigint unsigned NOT NULL DEFAULT 0, -- ("DEFAULT 0" is temporary, signaling that pt_reason should be used)
    pt_timestamp binary(14) NOT NULL,
    pt_expiry varbinary(14) NOT NULL default '',
    pt_create_perm varbinary(60) NOT NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/pt_namespace_title ON /*_*/protected_titles (pt_namespace,pt_title);
  CREATE INDEX /*i*/pt_timestamp ON /*_*/protected_titles (pt_timestamp);
  
  
  -- Name/value pairs indexed by page_id
  CREATE TABLE /*_*/page_props (
    pp_page int NOT NULL,
    pp_propname varbinary(60) NOT NULL,
    pp_value blob NOT NULL,
    pp_sortkey float DEFAULT NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/pp_page_propname ON /*_*/page_props (pp_page,pp_propname);
  CREATE UNIQUE INDEX /*i*/pp_propname_page ON /*_*/page_props (pp_propname,pp_page);
  CREATE UNIQUE INDEX /*i*/pp_propname_sortkey_page ON /*_*/page_props (pp_propname,pp_sortkey,pp_page);
  
  -- A table to log updates, one text key row per update.
  CREATE TABLE /*_*/updatelog (
    ul_key varchar(255) NOT NULL PRIMARY KEY,
    ul_value blob
  ) /*$wgDBTableOptions*/;
  
  
  -- A table to track tags for revisions, logs and recent changes.
  CREATE TABLE /*_*/change_tag (
    ct_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
    -- RCID for the change
    ct_rc_id int NULL,
    -- LOGID for the change
    ct_log_id int unsigned NULL,
    -- REVID for the change
    ct_rev_id int unsigned NULL,
    -- Tag applied
    ct_tag varchar(255) NOT NULL,
    -- Parameters for the tag, presently unused
    ct_params blob NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/change_tag_rc_tag ON /*_*/change_tag (ct_rc_id,ct_tag);
  CREATE UNIQUE INDEX /*i*/change_tag_log_tag ON /*_*/change_tag (ct_log_id,ct_tag);
  CREATE UNIQUE INDEX /*i*/change_tag_rev_tag ON /*_*/change_tag (ct_rev_id,ct_tag);
  -- Covering index, so we can pull all the info only out of the index.
  CREATE INDEX /*i*/change_tag_tag_id ON /*_*/change_tag (ct_tag,ct_rc_id,ct_rev_id,ct_log_id);
  
  
  -- Rollup table to pull a LIST of tags simply without ugly GROUP_CONCAT
  -- that only works on MySQL 4.1+
  CREATE TABLE /*_*/tag_summary (
    ts_id int unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT,
    -- RCID for the change
    ts_rc_id int NULL,
    -- LOGID for the change
    ts_log_id int unsigned NULL,
    -- REVID for the change
    ts_rev_id int unsigned NULL,
    -- Comma-separated list of tags
    ts_tags blob NOT NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/tag_summary_rc_id ON /*_*/tag_summary (ts_rc_id);
  CREATE UNIQUE INDEX /*i*/tag_summary_log_id ON /*_*/tag_summary (ts_log_id);
  CREATE UNIQUE INDEX /*i*/tag_summary_rev_id ON /*_*/tag_summary (ts_rev_id);
  
  
  CREATE TABLE /*_*/valid_tag (
    vt_tag varchar(255) NOT NULL PRIMARY KEY
  ) /*$wgDBTableOptions*/;
  
  -- Table for storing localisation data
  CREATE TABLE /*_*/l10n_cache (
    -- Language code
    lc_lang varbinary(32) NOT NULL,
    -- Cache key
    lc_key varchar(255) NOT NULL,
    -- Value
    lc_value mediumblob NOT NULL,
    PRIMARY KEY (lc_lang, lc_key)
  ) /*$wgDBTableOptions*/;
  
  -- Table caching which local files a module depends on that aren't
  -- registered directly, used for fast retrieval of file dependency.
  -- Currently only used for tracking images that CSS depends on
  CREATE TABLE /*_*/module_deps (
    -- Module name
    md_module varbinary(255) NOT NULL,
    -- Module context vary (includes skin and language; called "md_skin" for legacy reasons)
    md_skin varbinary(32) NOT NULL,
    -- JSON blob with file dependencies
    md_deps mediumblob NOT NULL,
    PRIMARY KEY (md_module,md_skin)
  ) /*$wgDBTableOptions*/;
  
  -- Holds all the sites known to the wiki.
  CREATE TABLE /*_*/sites (
    -- Numeric id of the site
    site_id                    INT UNSIGNED        NOT NULL PRIMARY KEY AUTO_INCREMENT,
  
    -- Global identifier for the site, ie 'enwiktionary'
    site_global_key            varbinary(32)       NOT NULL,
  
    -- Type of the site, ie 'mediawiki'
    site_type                  varbinary(32)       NOT NULL,
  
    -- Group of the site, ie 'wikipedia'
    site_group                 varbinary(32)       NOT NULL,
  
    -- Source of the site data, ie 'local', 'wikidata', 'my-magical-repo'
    site_source                varbinary(32)       NOT NULL,
  
    -- Language code of the sites primary language.
    site_language              varbinary(32)       NOT NULL,
  
    -- Protocol of the site, ie 'http://', 'irc://', '//'
    -- This field is an index for lookups and is build from type specific data in site_data.
    site_protocol              varbinary(32)       NOT NULL,
  
    -- Domain of the site in reverse order, ie 'org.mediawiki.www.'
    -- This field is an index for lookups and is build from type specific data in site_data.
    site_domain                VARCHAR(255)        NOT NULL,
  
    -- Type dependent site data.
    site_data                  BLOB                NOT NULL,
  
    -- If site.tld/path/key:pageTitle should forward users to  the page on
    -- the actual site, where "key" is the local identifier.
    site_forward              bool                NOT NULL,
  
    -- Type dependent site config.
    -- For instance if template transclusion should be allowed if it's a MediaWiki.
    site_config               BLOB                NOT NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/sites_global_key ON /*_*/sites (site_global_key);
  CREATE INDEX /*i*/sites_type ON /*_*/sites (site_type);
  CREATE INDEX /*i*/sites_group ON /*_*/sites (site_group);
  CREATE INDEX /*i*/sites_source ON /*_*/sites (site_source);
  CREATE INDEX /*i*/sites_language ON /*_*/sites (site_language);
  CREATE INDEX /*i*/sites_protocol ON /*_*/sites (site_protocol);
  CREATE INDEX /*i*/sites_domain ON /*_*/sites (site_domain);
  CREATE INDEX /*i*/sites_forward ON /*_*/sites (site_forward);
  
  -- Links local site identifiers to their corresponding site.
  CREATE TABLE /*_*/site_identifiers (
    -- Key on site.site_id
    si_site                    INT UNSIGNED        NOT NULL,
  
    -- local key type, ie 'interwiki' or 'langlink'
    si_type                    varbinary(32)       NOT NULL,
  
    -- local key value, ie 'en' or 'wiktionary'
    si_key                     varbinary(32)       NOT NULL
  ) /*$wgDBTableOptions*/;
  
  CREATE UNIQUE INDEX /*i*/site_ids_type ON /*_*/site_identifiers (si_type, si_key);
  CREATE INDEX /*i*/site_ids_site ON /*_*/site_identifiers (si_site);
  CREATE INDEX /*i*/site_ids_key ON /*_*/site_identifiers (si_key);
  
  -- vim: sw=2 sts=2 et
  