Available from version 1.30.0 (Gerrit change 351146)
Called when old recentchanges rows are purged, after deleting those rows but within the same transaction.
Define function:
public static function onRecentChangesPurgeRows( array $rows ) { ... }
Attach hook:

In extension.json:

	"Hooks": {
		"RecentChangesPurgeRows": "MyExtensionHooks::onRecentChangesPurgeRows"

For MediaWiki ≤1.25:

$wgHooks['RecentChangesPurgeRows'][] = 'MyExtensionHooks::onRecentChangesPurgeRows';
Called from:File(s): jobqueue/jobs/RecentChangesUpdateJob.php
Function(s): purgeExpiredRows

For more information about attaching hooks, see Manual:Hooks.
For examples of extensions using this hook, see Category:RecentChangesPurgeRows extensions.