diff --git a/modules/mining-checker/src/Infrastructure/SchemaManager.php b/modules/mining-checker/src/Infrastructure/SchemaManager.php
index 2bd049d..bca4937 100644
--- a/modules/mining-checker/src/Infrastructure/SchemaManager.php
+++ b/modules/mining-checker/src/Infrastructure/SchemaManager.php
@@ -429,19 +429,18 @@ final class SchemaManager
                 $this->pdo->beginTransaction();
             }
 
-            $executed = 0;
+            $normalizedStatements = [];
             foreach ($statements as $statement) {
                 $trimmed = trim($statement);
                 if ($trimmed === '') {
                     continue;
                 }
 
-                $normalizedStatement = $this->normalizeImportStatement($trimmed);
-                $currentStatement = $normalizedStatement;
-                $this->pdo->exec($normalizedStatement);
-                $executed++;
+                $normalizedStatements[] = $this->normalizeImportStatement($trimmed);
             }
 
+            $executed = $this->executeImportPass($normalizedStatements, $currentStatement);
+
             if ($useTransaction && $this->pdo->inTransaction()) {
                 $this->pdo->commit();
             }
@@ -464,6 +463,65 @@ final class SchemaManager
         }
     }
 
+    /**
+     * @param list<string> $statements
+     */
+    private function executeImportPass(array $statements, ?string &$currentStatement): int
+    {
+        $pendingStatements = $statements;
+        $executed = 0;
+        $maxPasses = max(1, count($pendingStatements));
+
+        for ($pass = 0; $pass < $maxPasses && $pendingStatements !== []; $pass++) {
+            $deferredStatements = [];
+            $progressMade = false;
+
+            foreach ($pendingStatements as $statement) {
+                $currentStatement = $statement;
+
+                try {
+                    $this->pdo->exec($statement);
+                    $executed++;
+                    $progressMade = true;
+                } catch (\Throwable $exception) {
+                    if ($this->shouldRetryDeferredImportStatement($exception, $statement)) {
+                        $deferredStatements[] = $statement;
+                        continue;
+                    }
+
+                    throw $exception;
+                }
+            }
+
+            if ($deferredStatements === []) {
+                return $executed;
+            }
+
+            if (!$progressMade) {
+                $currentStatement = $deferredStatements[0];
+                $this->pdo->exec($deferredStatements[0]);
+            }
+
+            $pendingStatements = $deferredStatements;
+        }
+
+        return $executed;
+    }
+
+    private function shouldRetryDeferredImportStatement(\Throwable $exception, string $statement): bool
+    {
+        if ($this->driver !== 'pgsql') {
+            return false;
+        }
+
+        if (!preg_match('/^(INSERT|COPY)\\b/i', ltrim($statement))) {
+            return false;
+        }
+
+        $errorCode = (string) $exception->getCode();
+        return $errorCode === '23503';
+    }
+
     private function normalizeImportStatement(string $statement): string
     {
         if ($this->driver !== 'pgsql') {