12fb06e3b4e29b23432bb6b2b8d47b75afd9b3a4
[lhc/web/wiklou.git] / RELEASE-NOTES-1.27
1 == MediaWiki 1.27 ==
2
3 THIS IS NOT A RELEASE YET
4
5 MediaWiki 1.27 is an alpha-quality branch and is not recommended for use in
6 production.
7
8 === PHP version requirement ===
9 As of 1.27, MediaWiki now requires PHP 5.5.9 or higher. This corresponds with
10 HHVM 3.1.
11
12 === Configuration changes in 1.27 ===
13 * $wgAllowMicrodataAttributes and $wgAllowRdfaAttributes were removed,
14 now always enabled. If you use RDFa on your wiki, you now have to explicitly
15 set $wgHtml5Version to 'HTML+RDFa 1.0' or 'XHTML+RDFa 1.0'.
16 * $wgUseLinkNamespaceDBFields was removed.
17 * Deprecated $wgResourceLoaderMinifierStatementsOnOwnLine and
18 $wgResourceLoaderMinifierMaxLineLength, because there was little value in
19 making the behavior configurable. The default values (`false` for the former,
20 1000 for the latter) are now hard-coded.
21 * $wgDebugDumpSqlLength was removed (deprecated in 1.24).
22 * $wgDebugDBTransactions was removed (deprecated in 1.20).
23 * $wgUseXVO has been removed, as it provides functionality only used by
24 custom Wikimedia patches against Squid 2.x that probably noone uses in
25 production anymore. There is now $wgUseKeyHeader that provides similar
26 functionality but instead of the MediaWiki-specific X-Vary-Options header,
27 uses the draft Key header standard.
28 * $wgScriptExtension (and support for '.php5' entry points) was removed. See the
29 deprecation notice in the release notes for version 1.25 for advice on how to
30 preserve support for '.php5' entry points via URL rewriting.
31 * Password handling via the User object has been deprecated and partially
32 removed, pending the future introduction of AuthManager. In particular:
33 ** expirePassword(), getPasswordExpireDate(), resetPasswordExpiration(), and
34 getPasswordExpired() have been removed. They were unused outside of core.
35 ** The mPassword, mNewpassword, mNewpassTime, and mPasswordExpires fields are
36 now private and will be removed in the future.
37 ** The getPassword() and getTemporaryPassword() methods now throw
38 BadMethodCallException and will be removed in the future.
39 ** The ability to pass 'password' and 'newpassword' to createNew() has been
40 removed. The only users of it seem to have been using it to set invalid
41 passwords, and so shouldn't be greatly affected.
42 ** setPassword(), setInternalPassword(), and setNewpassword() have been
43 deprecated, pending the introduction of AuthManager.
44 ** User::randomPassword() is deprecated in favor of a new method
45 PasswordFactory::generateRandomPasswordString()
46 ** User::getPasswordFactory() is deprecated, callers should just create a
47 PasswordFactory themselves.
48 ** A new constructor, User::newSystemUser(), has been added to simplify the
49 creation of passwordless "system" users for logged actions.
50 * $wgMaxSquidPurgeTitles was removed.
51 * $wgAjaxWatch was removed. This is now enabled by default.
52 * $wgUseInstantCommons now hotlinks Commons images by default instead of
53 downloading originals and thumbnailing them locally. This allows wikis to save
54 on CPU and bandwidth while reducing time to first byte for pages, even without
55 a thumbnail handler. See $wgForeignFileRepos documentation for tweaks.
56 * (T27397) WebP is enabled by default as an uploadable filetype.
57 * (T48998) $wgArticlePath must now be either a full url, or start with a "/".
58 * $wgRateLimitLog was removed; use $wgDebugLogGroups['ratelimit'] instead.
59 * Deprecated API formats dbg, txt, and yaml have been removed.
60 * CLDRPluralRule* classes have been replaced with
61 wikimedia/cldr-plural-rule-parser.
62 * Removed $wgProfilePerHost, $wgUDPProfilerHost, $wgUDPProfilerPort,
63 $wgUDPProfilerFormatString, $wgStatsMethod, $wgAggregateStatsID,
64 $wgStatsFormatString, and $wgProfileCallTree (deprecated since 1.20).
65 * For proper operation of LocalIdLookup with shared user tables, ensure that
66 $wgSharedDB and $wgSharedTables are properly set even on the "central" wiki
67 that all others are sharing from and that $wgLocalDatabases is set to the
68 full list of sharing wikis on all those wikis.
69 * Massive overhaul to session handling:
70 ** $wgSessionsInObjectCache is no longer supported and must be true, due to
71 MediaWiki\Session\SessionManager. $wgSessionHandler is similarly no longer
72 used.
73 ** ObjectCacheSessionHandler is removed, replaced with
74 MediaWiki\Session\PhpSessionHandler.
75 ** PHP session handling in general ($_SESSION, session_id(), and so on) is
76 deprecated. Use MediaWiki\Session\SessionManager instead. A new config
77 variable, $wgPHPSessionHandling, is available to cause use of $_SESSION to
78 issue a deprecation warning or to cause most PHP session handling to throw
79 exceptions.
80 ** Deprecated UserSetCookies hook. Session-handling extensions should generally
81 be creating a custom subclass of CookieSessionProvider. Other extensions
82 messing with cookies can no longer count on user data being saved in cookies
83 versus other methods.
84 ** Deprecated UserLoadFromSession hook, extensions should create a
85 MediaWiki\Session\SessionProvider.
86 ** The User cannot be loaded from session until after Setup.php completes.
87 Attempts to do so will be ignored and the User will remain unloaded.
88 ** CSRF tokens may be fetched from the MediaWiki\Session\Session, which uses
89 the MediaWiki\Session\Token class.
90 * MediaWiki will now auto-create users as necessary, removing the need for
91 extensions to do so. An 'autocreateaccount' right is added to allow
92 auto-creation when 'createaccount' is not granted to all users.
93 * Deprecated AuthPluginAutoCreate hook in favor of LocalUserCreated.
94 * Most cookie-handling methods in User are deprecated.
95 * $wgAllowAsyncCopyUploads and $CopyUploadAsyncTimeout were removed. This was an
96 experimental feature that has never worked.
97 * Login and createaccount tokens now vary by timestamp.
98 * LoginForm::getLoginToken() and LoginForm::getCreateaccountToken()
99 return a MediaWiki\Session\Token, and tokens must be checked using that
100 class's methods.
101 * $wgEnotifUseJobQ was removed and the job queue is always used.
102 * The functionality of the ApiSandbox extension has been merged into core. The
103 extension should no longer be used.
104 * $wgPreloadJavaScriptMwUtil was removed (deprecated in 1.26).
105 Extensions, skins, gadgets and scripts that use the mediawiki.util module must
106 express a dependency on it.
107 * $wgIncludeLegacyJavaScript, deprecated in MediaWiki 1.26, now defaults false.
108 Extensions, skins, gadgets and scripts that need the mediawiki.legacy.wikibits
109 module should express a dependency on it.
110 * Removed configuration option $wgCopyrightIcon (deprecated since 1.18). Use
111 $wgFooterIcons['copyright']['copyright'] instead.
112
113 === New features in 1.27 ===
114 * $wgDataCenterUpdateStickTTL was also added. This decides how long a user
115 sticks to the primary DC (via cookies) after they make changes to the site.
116 * Added a new hook, 'UserMailerTransformContent', to transform the contents
117 of an email. This is similar to the EmailUser hook but applies to all mail
118 sent via UserMailer.
119 * Added a new hook, 'UserMailerTransformMessage', to transform the contents
120 of an emai after MIME encoding.
121 * Added a new hook, 'UserMailerSplitTo', to control which users have to be
122 emailed separately (ie. there is a single address in the To: field) so
123 user-specific changes to the email can be applied safely.
124 * $wgCdnMaxageLagged was added, which limits the CDN cache TTL
125 when any load balancer uses a DB that is lagged beyond the 'max lag'
126 setting in the relevant section of $wgLBFactoryConf.
127 * User::newSystemUser() may be used to simplify the creation of passwordless
128 "system" users for logged actions from scripts and extensions.
129 * Extensions can now return detailed error information via the API when
130 preventing user actions using 'getUserPermissionsErrors' and similar hooks
131 by using ApiMessage instances instead of strings for the $result value.
132 * $wgAPIMaxLagThreshold was added to limit bot changes when databases lag
133 becomes too high.
134 * Skins and extensions can now use FlexBox mixins (.flex-display(@display: flex)
135 and .flex(@grow: 1, @shrink: 1, @width: auto, @order: 1)) in Less to create
136 cross-browser-compatible FlexBox rules. Users will still need to add fallback
137 float rules or the like for compatibility with IE9- separately.
138 * Added MWTimestamp::getTimezoneString() which returns the localized timezone
139 string, if available. To localize this string, see the comments of
140 $wgLocaltimezone in includes/DefaultSettings.php.
141 * Added CentralIdLookup, a service that allows extensions needing a concept of
142 "central" users to get that without having to know about specific central
143 authentication extensions.
144 * $wgMaxUserDBWriteDuration added to limit huge user-generated transactions.
145 Regular web request transactions that takes longer than this are aborted.
146 * Added a new hook, 'TitleMoveCompleting', which runs before a page move is
147 committed.
148 * $wgCdnReboundPurgeDelay was added to provide secondary delayed purges of URLs
149 from CDN to mitigate DB replication lag and WAN cache purge lag.
150 * (T49162) Installer will default to setting CACHE_ACCEL as the main cache type
151 if it is available.
152 * It is now possible to patrol file uploads (both for new files and new versions
153 of existing files). Special:NewFiles has gained an option to filter by patrol
154 status. This functionality can be disabled using $wgUseFilePatrol.
155 * MediaWiki\Session infrastructure allows for easier use of session mechanisms
156 other than the usual cookies.
157 ** SessionMetadata and SessionCheckInfo hooks allow for setting and checking
158 custom session metadata.
159 * Added MWGrants and associated configuration settings $wgGrantPermissions and
160 $wgGrantPermissionGroups to hold configuration for authentication features
161 such as OAuth that want to allow restricting the user rights a user may make
162 use of.
163 ** If you're already using the OAuth extension, these new variables are
164 identical to (and will replace) $wgMWOAuthGrantPermissions and
165 $wgMWOAuthGrantPermissionGroups.
166 * Added MWRestrictions as a class to check restrictions on a WebRequest, e.g.
167 to assert that the request comes from a particular IP range.
168 * Added bot passwords, a rights-restricted login mechanism for API-using bots.
169 * Whitelisted the following HTML attributes for all elements in wikitext:
170 aria-describedby, aria-flowto, aria-label, aria-labelledby, aria-owns.
171 * Removed "presentation" restriction on the HTML role attribute in wikitext.
172 All values are now allowed for the role attribute.
173 * $wgContentHandlers now also supports callbacks to create an instance of the
174 appropriate ContentHandler subclass.
175 * Added $wgAuthenticationTokenVersion, which if non-null prevents the
176 user_token database field from being exposed in cookies. Setting this would
177 be a good idea, but will log out all current sessions.
178 * $wgEventRelayerConfig was added, for managing PubSub event relay configuration,
179 specifically for reliable CDN url purges.
180 * Requests have unique IDs, equal to the UNIQUE_ID environment variable (when
181 MediaWiki is behind Apache+mod_unique_id or something similar) or a randomly-
182 generated 24-character string. This request ID is used to annotate log records
183 and error messages. It is available client-side via mw.config.get( 'wgRequestId' ).
184 The request ID supplants exception IDs. Accordingly, MWExceptionHandler::getLogId()
185 is deprecated.
186
187 === External library changes in 1.27 ===
188
189 ==== Upgraded external libraries ====
190 * Updated oojs/oojs-ui from v0.12.12 to v0.13.3.
191 * Updated composer/semver from v1.0.0 to v1.2.0.
192 * Updated liuggio/statsd-php-client to 1.0.18.
193 * Updated QUnit from v1.18.0 to v1.22.0.
194
195 ==== New external libraries ====
196 * Added wikimedia/base-convert v1.0.1.
197 * Added wikimedia/cldr-plural-rule-parser v1.0.0.
198 * Added wikimedia/relpath v1.0.3.
199 * Added wikimedia/running-stat v1.1.0.
200 * Added wikimedia/php-session-serializer v1.0.3.
201
202 ==== Removed and replaced external libraries ====
203
204 === Bug fixes in 1.27 ===
205 * Special:Upload will now display correct maximum allowed file size when running
206 under HHVM (T116347).
207
208 === Action API changes in 1.27 ===
209 * Added list=allrevisions.
210 * generator=recentchanges now has the option to generate revids.
211 * ApiPageSet::setRedirectMergePolicy() was added. This allows generator
212 modules to define how generator data for a redirect source gets merged
213 into the redirect destination.
214 * prop=imageinfo&iiprop=uploadwarning will no longer include the possibility of
215 "was-deleted" warning.
216 * Added difftotextpst to query=revisions which preforms a pre-save transform on
217 the text before diffing it.
218 * Deprecated formats dbg, txt, and yaml have been removed.
219 * (T47988) The protect log event details now use new-style formatting.
220 * The following response properties from action=login are deprecated, and may
221 be removed in the future: lgtoken, cookieprefix, sessionid. Clients should
222 handle cookies to properly manage session state.
223 * action=login transparently allows login using bot passwords. Clients should
224 merely need to change the username and password used after setting up a bot
225 password.
226 * action=upload no longer understands statuskey, asyncdownload or leavemessage.
227
228 === Action API internal changes in 1.27 ===
229 * ApiQueryORM removed.
230 * The following classes have been removed:
231 ** ApiFormatDbg
232 ** ApiFormatTxt
233 ** ApiFormatYaml
234 * ApiBase::addTokenProperties() was removed (deprecated since 1.24).
235 * ApiBase::getFinalPossibleErrors() was removed (deprecated since 1.24).
236 * ApiBase::getFinalResultProperties() was removed (deprecated since 1.24).
237 * ApiBase::getRequireAtLeastOneParameterErrorMessages() was removed (deprecated since 1.24).
238 * ApiBase::getPossibleErrors() was removed (deprecated since 1.24).
239 * ApiBase::getRequireMaxOneParameterErrorMessages() was removed (deprecated since 1.24).
240 * ApiBase::getRequireOnlyOneParameterErrorMessages() was removed (deprecated since 1.24).
241 * ApiBase::getResultProperties() was removed (deprecated since 1.24).
242 * ApiBase::getTitleOrPageIdErrorMessage() was removed (deprecated since 1.24).
243 * ApiBase::parseErrors() was removed (deprecated since 1.24).
244 * ApiQueryBase::titleToKey(), ApiQueryBase::keyToTitle() and
245 ApiQueryBase::keyPartToTitle() all removed (deprecated since 1.24).
246 * ApiQueryBase::checkRowCount() was removed (deprecated since 1.24).
247 * ApiQueryBase::getDirectionDescription() was removed (deprecated since 1.25).
248 * ApiQuery::getGenerators() was removed (deprecated since 1.21).
249 * ApiQuery::getModules() was removed (deprecated since 1.21).
250 * ApiQuery::getModuleType() was removed (deprecated since 1.21).
251 * ApiQuery::setGeneratorContinue() was removed (deprecated since 1.24).
252 * ApiMain::getModules() was removed (deprecated since 1.21).
253 * ApiBase::getVersion() was removed (deprecated since 1.21).
254 * ApiMain::getShowVersions() was removed (deprecated in 1.21).
255 * ApiMain::addModule() was removed (deprecated in 1.21).
256 * ApiMain::addFormat() was removed (deprecated in 1.21).
257 * ApiMain::getFormats() was removed (deprecated in 1.21).
258 * ApiPageSet::finishPageSetGeneration() was removed (deprecated in 1.21).
259
260 === Languages updated in 1.27 ===
261
262 MediaWiki supports over 350 languages. Many localisations are updated
263 regularly. Below only new and removed languages are listed, as well as
264 changes to languages because of Phabricator reports.
265
266 * (T113688) Change default numerals from Gurmukhi to Arabic for Punjabi locale.
267
268 === Other changes in 1.27 ===
269 * ProfilerOutputUdp was removed. Note that there is a ProfilerOutputStats class.
270 * WikiPage::doDeleteArticleReal() and WikiPage::doDeleteArticle() now
271 ignore the 2nd and 3rd arguments (formerly $id and $commit).
272 * Removed "loaderScripts" option from ResourceLoaderFileModule class.
273 * Removed ORM-like wrapper added in 1.20.
274 * LinkCache::getGoodLinks and LinkCache::getBadLinks were removed
275 (deprecated in 1.26).
276 * WikiPage::doQuickEdit() was removed (deprecated since 1.21).
277 * Removed SiteObject and SiteArray classes (deprecated in 1.21).
278 * MessageBlobStore::getInstance() was removed (deprecated since 1.25).
279 * (T84937) Free external links ("autolinked" urls) will now be terminated
280 by &nbsp; and HTML entity encodings of &nbsp, <, and >.
281 * (T36948) The default file revert message's timestamp is now in
282 $wgLocaltimezone, instead of UTC.
283 * The default name of the 'suppress' group page has been changed from
284 'Project:Oversight' to 'Project:Suppress'.
285 * DatabaseBase::resultObject() is now protected (use outside Database classes
286 not necessary since 1.11).
287 * Calling ResourceLoaderFileModule::readStyleFiles() without a
288 ResourceLoaderContext instance is deprecated.
289 * ResourceLoader::getLessCompiler() now takes an optional parameter of
290 additional LESS variables to set for the compiler.
291 * wfBaseConvert() marked as deprecated, use Wikimedia\base_convert() directly
292 instead.
293 * Obsolete maintenance scripts clearCacheStats.php and showCacheStats.php
294 were removed. The underlying data is sent to StatsD (see $wgStatsdServer).
295 * Removed msg_resource_links database table and associated code.
296 * Removed msg_resource database table and associated code.
297 * Skin::getNamespaceNotice() was removed.
298 * wfIsConfiguredProxy() was removed (deprecated since 1.24).
299 * wfDebugTimer() was removed (deprecated since 1.25).
300 * wfIsTrustedProxy() was removed (deprecated since 1.24).
301 * wfGetIP() was removed (deprecated since 1.19).
302 * MWHookException was removed.
303 * OutputPage::appendSubtitle() was removed (deprecated since 1.19).
304 * OutputPage::loginToUse() was removed (deprecated since 1.19).
305 * Article::loadContent() was removed (deprecated since 1.19).
306 * User::editToken() was removed (deprecated since 1.19).
307 * Removed --force-normal option of dumpBackup.php, as it no longer served
308 any useful purpose since 1.22.
309 * The functions processOption() and processArgs() on the BackupDumper and
310 TextPassDumper classes have been removed.
311 * The maintenance/backupTextPass.inc file was deleted. You should include
312 maintenance/dumpTextPass.php instead.
313 * WikiPage::getUsedTemplates() was removed (deprecated since 1.19).
314 * wfEmptyMsg() was removed (deprecated since 1.18).
315 * OutputPage::permissionRequired() was removed (deprecated since 1.18).
316 * OutputPage::blockedPage() was removed (deprecated since 1.18).
317 * User::getSkin() was removed (deprecated since 1.18).
318 * OutputPage::includeJQuery() was removed (deprecated since 1.17).
319 * WikiPage::updateRestrictions() was removed (deprecated since 1.19).
320 * WikiPage::testPreSaveTransform() was removed (deprecated since 1.19).
321 * LogPage::logName() was removed (deprecated since 1.19).
322 * LogPage::logHeader() was removed (deprecated since 1.19).
323 * wfCheckLimits() was removed (deprecated since 1.24).
324 * Linker::makeKnownLinkObj() was removed (deprecated since 1.16).
325 * Linker::makeLinkObj() was removed (deprecated since 1.16).
326 * wfMsgForContentNoTrans() was removed (deprecated since 1.18).
327 * ChangesList::usePatrol was removed (deprecated since 1.22).
328 * wfMsgNoTrans() was removed (deprecated since 1.18).
329 * Linker::makeImageLink2 was removed (deprecated since 1.20).
330 * Title::userIsWatching() was removed (deprecated since 1.20).
331 * Removed WaitForSlave maintenance script; use SELECT MASTER_POS_WAIT()
332 database function directly instead.
333 * wfMsg() was removed (deprecated since 1.18).
334 * wfMsgForContent() was removed (deprecated since 1.18).
335 * wfMsgReal() was removed (deprecated since 1.18).
336 * wfMsgGetKey() was removed (deprecated since 1.18).
337 * wfMsgHtml() was removed (deprecated since 1.18).
338 * wfMsgWikiHtml() was removed (deprecated since 1.18).
339 * wfMsgExt() was removed (deprecated since 1.18).
340 * Language::armourMath() was removed (deprecated since 1.22).
341 * LanguageConverter::armourMath() was removed (deprecated since 1.22).
342 * FakeConverter::armourMath() was removed (deprecated since 1.22).
343 * The unused jquery.validate ResourceLoader module was removed.
344 * FileRepo::getRootUrl() was removed (deprecated since 1.20).
345 * User::generateToken() was removed (deprecated since 1.20).
346 * WikiPage::getRawText() was removed (deprecated since 1.21).
347 * ParserOutput::hasCustomDataUpdates() was removed (deprecated since 1.25).
348 * ParserOutput::addSecondaryDataUpdate() was removed (deprecated since 1.25).
349 * ParserOutput::getSecondaryDataUpdates() was removed (deprecated since 1.25).
350 * Gallery images with multiple caption pipes no longer concatenate them all
351 together but instead pick the final one, similar to image syntax.
352 * XML-like parser tags (such as <gallery>), when unclosed, will be left unparsed
353 rather than consume everything until the end of the page.
354 * New maintenance script resetUserEmail.php allows sysadmins to reset user emails in case
355 a user forgot password/account was stolen.
356 * wfCheckEntropy() was removed (deprecated in 1.27).
357 * Browser support for Internet Explorer 8 lowered from Grade A to Grade C.
358 * ContentHandler::supportsCategories method added. Default is true.
359 CategoryMembershipChangeJob updates are skipped for content that
360 does not support categories.
361 * wikidiff difference engine is no longer supported, anyone still using it are encouraged
362 to upgrade to wikidiff2 which is actively maintained and has better package availability.
363 * Database logic was removed from WatchedItem and a WatchedItemStore was created:
364 ** WatchedItem::IGNORE_USER_RIGHTS and WatchedItem::CHECK_USER_RIGHTS were deprecated.
365 User::IGNORE_USER_RIGHTS and User::CHECK_USER_RIGHTS were introduced.
366 ** WatchedItem::fromUserTitle was deprecated in favour of the constructor.
367 ** WatchedItem::resetNotificationTimestamp was deprecated.
368 ** WatchedItem::batchAddWatch was deprecated.
369 ** WatchedItem::addWatch was deprecated.
370 ** WatchedItem::removeWatch was deprecated.
371 ** WatchedItem::isWatched was deprecated.
372 ** WatchedItem::duplicateEntries was deprecated.
373 ** EmailNotification::updateWatchlistTimestamp was deprecated.
374 ** User::getWatchedItem was removed.
375 * Unit tests don't work with external PHPUnit anymore, Composer is now the only supported
376 way. Run `composer install` to install it and other dev dependencies to run unit tests.
377 * wl_id field added to the watchlist table.
378 * Revision::getRawText() was removed (deprecated since 1.21).
379 * WikiPage::replaceSection() was removed (deprecated since 1.21).
380 * Article::replaceSection() was removed (deprecated since 1.21).
381 * Language::getLangObj() was removed (deprecated since 1.24).
382 * Language::getLanguageName() was removed (deprecated since 1.20).
383 * Language::getLanguageNames() was removed (deprecated since 1.20).
384 * Language::getTranslatedLanguageNames() was removed (deprecated since 1.20).
385 * Language::specialPage() was removed (deprecated since 1.24).
386 * MediaWikiTestCase::assertException() was removed (deprecated since 1.22).
387 * OutputPage::getHeadItems() was removed (deprecated since 1.24).
388 * OutputPage::getScript() was removed (deprecated since 1.24).
389 * OutputPage::out() was removed (deprecated since 1.22).
390 * OutputPage::setAllowedModules() was removed (deprecated since 1.24).
391 * UserrightsPage::makeGroupNameListForLog() was removed (deprecated since 1.21).
392 * MediaWikiSite::newFromGlobalId() was removed (deprecated since 1.21).
393 * Title::newFromRedirect() was removed (deprecated since 1.21).
394 * Skin::commonPrintStylesheet() was removed (deprecated since 1.22).
395 * Skin::getCommonStylePath() was removed (deprecated since 1.24).
396 * Skin::newFromKey() was removed (deprecated since 1.24).
397 * Skin::getUsableSkins() was removed (deprecated since 1.23).
398 * LoadBalancer::pickRandom() was removed (deprecated in 1.21).
399
400 == Compatibility ==
401
402 MediaWiki 1.27 requires PHP 5.5.9 or later. There is experimental support for
403 HHVM 3.6.5 or later.
404
405 MySQL is the recommended DBMS. PostgreSQL or SQLite can also be used, but
406 support for them is somewhat less mature. There is experimental support for
407 Oracle and Microsoft SQL Server.
408
409 The supported versions are:
410
411 * MySQL 5.0.3 or later
412 * PostgreSQL 8.3 or later
413 * SQLite 3.3.7 or later
414 * Oracle 9.0.1 or later
415 * Microsoft SQL Server 2005 (9.00.1399)
416
417 == Upgrading ==
418
419 1.27 has several database changes since 1.26, and will not work without schema
420 updates. Note that due to changes to some very large tables like the revision
421 table, the schema update may take quite long (minutes on a medium sized site,
422 many hours on a large site).
423
424 If upgrading from before 1.11, and you are using a wiki as a commons
425 repository, make sure that it is updated as well. Otherwise, errors may arise
426 due to database schema changes.
427
428 If upgrading from before 1.7, you may want to run refreshLinks.php to ensure
429 new database fields are filled with data.
430
431 If you are upgrading from MediaWiki 1.4.x or earlier, you should upgrade to
432 1.5 first. The upgrade script maintenance/upgrade1_5.php has been removed
433 with MediaWiki 1.21.
434
435 Don't forget to always back up your database before upgrading!
436
437 See the file UPGRADE for more detailed upgrade instructions.
438
439 For notes on 1.26.x and older releases, see HISTORY.
440
441 == Online documentation ==
442
443 Documentation for both end-users and site administrators is available on
444 MediaWiki.org, and is covered under the GNU Free Documentation License (except
445 for pages that explicitly state that their contents are in the public domain):
446
447 https://www.mediawiki.org/wiki/Documentation
448
449 == Mailing list ==
450
451 A mailing list is available for MediaWiki user support and discussion:
452
453 https://lists.wikimedia.org/mailman/listinfo/mediawiki-l
454
455 A low-traffic announcements-only list is also available:
456
457 https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce
458
459 It's highly recommended that you sign up for one of these lists if you're
460 going to run a public MediaWiki, so you can be notified of security fixes.
461
462 == IRC help ==
463
464 There's usually someone online in #mediawiki on irc.freenode.net.