The callers such as RL and GlobalCssJs are doing the right thing. They have the reasonable expectation that idoms like User::newFromName do the right thing.

For the user row, User::loadFromId > User::loadFromCache includes an in-memory cache which is working fine:

		$cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
		$data = $cache->getWithSetCallback(
			$this->getCacheKey( $cache ),
			$cache::TTL_HOUR,
			function () { ... },
			[ 'pcTTL' => $cache::TTL_PROC_LONG, ... ]
		);

However, before this, User::load, when the object is created with either mFrom=name or mFrom=actor, there is an uncached actor table query to resolve the name to an ID.

	public function load( $flags = ... ) {
		...

		switch ( $this->mFrom ) {
			case 'defaults':
				...
				break;
			case 'id':
				...
				$this->loadFromId( $flags );
				break;
			case 'actor':
			case 'name':
				$dbr = ...;
				$queryBuilder = $dbr->newSelectQueryBuilder()
					->select( [ 'actor_id', 'actor_user', 'actor_name' ] )
					->from( 'actor' )
					->...->fetchRow();

				if ( ... ) {
					$this->mId = $row->actor_user;
					$this->loadFromId( $flags );
				} else {...}
				break;

The way this fell apart:

• Historically, User::newFromName led to User::load using an in-class memory cache via User::idFromName from the above switch statement
• Feb 2018 (https://gerrit.wikimedia.org/r/380669: Add actor table T167246): Introduces User::newFromActorId with a new uncached actor table query for a new "actor" switch case. This method is more or less unused.
• Sep 2019 (https://gerrit.wikimedia.org/r/525605: Mostly drop old pre-actor T188327): Consolidates the "name" and "actor" cases, favoring the uncached actor table query, and leaving User::idFromName unused.
• May 2021 (https://gerrit.wikimedia.org/r/677365: Move idFromName cache to ActorStore): Also known as UserIdentityLookup.
• Jan 2023 (https://gerrit.wikimedia.org/r/879916: Deprecate idFromName). And subsequently removed as part of T325687: Hard-deprecate User::idFromName (and remove in 1.41).

Should be easy to adopt ActorStore there to bring this back. That should reduce from 3 down to 1 actor_name queries. Or, with a bit of luck to 0 actor_name queries, because ActorStore populates its cache in both directions, and chances are that the current user was already loaded from user ID rather than user name by AuthManager.

Thank you for looking into this. I have sent you down a rabbit hole. Sorry 😅 I take a look and see what I can do to reduce the queries.

Change #1334061 had a related patch set uploaded (by Milazg; author: Milazg):

[mediawiki/core@master] User: Use ActorStore on User::load

https://gerrit.wikimedia.org/r/1334061

Change #1335290 had a related patch set uploaded (by Krinkle; author: Krinkle):

[mediawiki/core@master] phpunit: Fix inconsistent user_id in LogFormatterTestCase

https://gerrit.wikimedia.org/r/1335290

Change #1335290 merged by jenkins-bot:

[mediawiki/core@master] phpunit: Fix inconsistent user_id in LogFormatterTestCase

https://gerrit.wikimedia.org/r/1335290

Change #1336613 had a related patch set uploaded (by Krinkle; author: Milazg):

[mediawiki/core@wmf/1.47.0-wmf.18] User: Use ActorStore on User::load

https://gerrit.wikimedia.org/r/1336613

Change #1336613 merged by jenkins-bot:

[mediawiki/core@wmf/1.47.0-wmf.18] User: Use ActorStore on User::load

https://gerrit.wikimedia.org/r/1336613

Change #1334061 merged by jenkins-bot:

[mediawiki/core@master] User: Use ActorStore on User::load

https://gerrit.wikimedia.org/r/1334061

Mentioned in SAL (#wikimedia-operations) [2026-09-07T13:59:48Z] <krinkle@deploy1003> Started scap sync-world: Backport for [[gerrit:1335754|tests: Add user_id and actor in testLogDatabaseRowsForHiddenUser (T436971)]], [[gerrit:1336613|User: Use ActorStore on User::load (T428517)]], [[gerrit:rEVED13357529e57a|Fix empty bases in m(under|over) (T436876)]], [[gerrit:1336611|Use Core-compatible output for cancellation (T379359)]], [[gerrit:1336609|Page: Fix absence caching when combined with mult

Mentioned in SAL (#wikimedia-operations) [2026-09-07T14:04:06Z] <krinkle@deploy1003> krinkle: Backport for [[gerrit:1335754|tests: Add user_id and actor in testLogDatabaseRowsForHiddenUser (T436971)]], [[gerrit:1336613|User: Use ActorStore on User::load (T428517)]], [[gerrit:rEVED13357529e57a|Fix empty bases in m(under|over) (T436876)]], [[gerrit:1336611|Use Core-compatible output for cancellation (T379359)]], [[gerrit:1336609|Page: Fix absence caching when combined with multiple properties

Mentioned in SAL (#wikimedia-operations) [2026-09-07T14:11:43Z] <krinkle@deploy1003> Finished scap sync-world: Backport for [[gerrit:1335754|tests: Add user_id and actor in testLogDatabaseRowsForHiddenUser (T436971)]], [[gerrit:1336613|User: Use ActorStore on User::load (T428517)]], [[gerrit:rEVED13357529e57a|Fix empty bases in m(under|over) (T436876)]], [[gerrit:1336611|Use Core-compatible output for cancellation (T379359)]], [[gerrit:1336609|Page: Fix absence caching when combined with mul

After the fix we have ~66.6% reduction in actor table lookups, from 3 queries to 1 for each page view request.
Before the change the same query ran 3 times

MediaWiki\User\User::load [3.269ms] [1 rows] db1271: SELECT  actor_id,actor_user,actor_name  FROM `actor`    WHERE actor_name = 'Peterxy'  LIMIT 1

After the deployment, we can see the lookup now happens once and goes through ActorStore

MediaWiki\User\ActorStore::getUserIdentityByName [0.876ms] [1 rows] db1195: SELECT  actor_id,actor_name,actor_user  FROM `actor`    WHERE actor_name = 'MGoncalves-WMF'  LIMIT 1

logstash: https://logstash.wikimedia.org/goto/35c2afe48559aca3a157d61fc36d6cff

Awesome. Thank you!