TYPO3 Core

Further research suggests that this is an issue of doctrine/dbal: https://github.com/doctrine/dbal/blob/2.12.x/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php#L713

I actually had that error in a fresh 12.4 setup (the missing quotes, not the case sensitivity), but the error came from doctrine itself. If i remember correctly, it could not deal with index names that start numerically.

Patching doctrine with composer-patches fixed it for me, maybe this can be of help

Index: src/Platforms/PostgreSQLPlatform.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/Platforms/PostgreSQLPlatform.php b/src/Platforms/PostgreSQLPlatform.php
--- a/src/Platforms/PostgreSQLPlatform.php    
+++ b/src/Platforms/PostgreSQLPlatform.php    (date 1715367310975)
@@ -746,7 +746,7 @@
             $oldIndexName = $schema . '.' . $oldIndexName;
         }

-        return ['ALTER INDEX ' . $oldIndexName . ' RENAME TO ' . $index->getQuotedName($this)];
+        return ['ALTER INDEX "' . $oldIndexName . '" RENAME TO ' . $index->getQuotedName($this)];
     }

     /**

Patch set 2 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/84576

Patch set 3 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/84576

Patch set 4 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/84576

Patch set 5 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/84576

Patch set 1 for branch 12.4 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/84698