**Steps to replicate the issue** (include links if applicable):
* Check out MW before a2ba7ee14d6b38a5e89bcc63c3bd0ca8b5107702 or use say 1.42.3
* Install MW on PostgreSQL
* Update the source tree to after a2ba7ee14d6b38a5e89bcc63c3bd0ca8b5107702
* Run update.php
**What happens?**:
```
Wikimedia\Rdbms\DBQueryError from line 1195 of /srv/mw/core/includes/libs/rdbms/database/Database.php: Error 42601: ERROR: syntax error at or near "PRIMARY"
LINE 1: ...gresUpdater::renameIndex */ INDEX si_page RENAME TO PRIMARY
^
Function: MediaWiki\Installer\PostgresUpdater::renameIndex
Query: ALTER INDEX si_page RENAME TO PRIMARY
#0 /srv/mw/core/includes/libs/rdbms/database/Database.php(1179): Wikimedia\Rdbms\Database->getQueryException('ERROR: syntax ...', '42601', 'ALTER INDEX si_...', 'MediaWiki\\Insta...')
#1 /srv/mw/core/includes/libs/rdbms/database/Database.php(1153): Wikimedia\Rdbms\Database->getQueryExceptionAndLog('ERROR: syntax ...', '42601', 'ALTER INDEX si_...', 'MediaWiki\\Insta...')
#2 /srv/mw/core/includes/libs/rdbms/database/Database.php(647): Wikimedia\Rdbms\Database->reportQueryError('ERROR: syntax ...', '42601', 'ALTER INDEX si_...', 'MediaWiki\\Insta...', false)
#3 /srv/mw/core/includes/libs/rdbms/database/DBConnRef.php(127): Wikimedia\Rdbms\Database->query(Object(Wikimedia\Rdbms\Query), 'MediaWiki\\Insta...', 0)
#4 /srv/mw/core/includes/libs/rdbms/database/DBConnRef.php(302): Wikimedia\Rdbms\DBConnRef->__call('query', Array)
#5 /srv/mw/core/includes/installer/PostgresUpdater.php(669): Wikimedia\Rdbms\DBConnRef->query('ALTER INDEX si_...', 'MediaWiki\\Insta...')
#6 /srv/mw/core/includes/installer/DatabaseUpdater.php(595): MediaWiki\Installer\PostgresUpdater->renameIndex('searchindex', 'si_page', 'PRIMARY', false, 'patch-searchind...')
#7 /srv/mw/core/includes/installer/DatabaseUpdater.php(548): MediaWiki\Installer\DatabaseUpdater->runUpdates(Array, false)
#8 /srv/mw/core/maintenance/update.php(195): MediaWiki\Installer\DatabaseUpdater->doUpdates(Array)
#9 /srv/mw/core/maintenance/includes/MaintenanceRunner.php(703): UpdateMediaWiki->execute()
#10 /srv/mw/core/maintenance/run.php(51): MediaWiki\Maintenance\MaintenanceRunner->run()
#11 {main}
```
**What should have happened instead?**:
No error.
**Other information** (browser name/version, screenshots, etc.):
The patch is documented as not actually doing anything on PostgreSQL, it's just for consistency.
---
Related/Caused by: {T249976}, {T231827}