diff --git a/core/Command/Db/ConvertType.php b/core/Command/Db/ConvertType.php
index 9b8284c930..f05014936f 100644
--- a/core/Command/Db/ConvertType.php
+++ b/core/Command/Db/ConvertType.php
@@ -28,6 +28,8 @@
 
 namespace OC\Core\Command\Db;
 
+use Doctrine\DBAL\DBALException;
+use Doctrine\DBAL\Schema\Table;
 use OC\DB\MigrationService;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use \OCP\IConfig;
@@ -271,24 +273,23 @@ class ConvertType extends Command implements CompletionAwareInterface {
 	/**
 	 * @param Connection $fromDB
 	 * @param Connection $toDB
-	 * @param $table
+	 * @param Table $table
 	 * @param InputInterface $input
 	 * @param OutputInterface $output
 	 * @suppress SqlInjectionChecker
 	 */
-	protected function copyTable(Connection $fromDB, Connection $toDB, $table, InputInterface $input, OutputInterface $output) {
-		if ($table === $toDB->getPrefix() . 'migrations') {
+	protected function copyTable(Connection $fromDB, Connection $toDB, Table $table, InputInterface $input, OutputInterface $output) {
+		if ($table->getName() === $toDB->getPrefix() . 'migrations') {
 			$output->writeln('<comment>Skipping migrations table because it was already filled by running the migrations</comment>');
 			return;
 		}
 
-
 		$chunkSize = $input->getOption('chunk-size');
 
 		$query = $fromDB->getQueryBuilder();
 		$query->automaticTablePrefix(false);
 		$query->selectAlias($query->createFunction('COUNT(*)'), 'num_entries')
-			->from($table);
+			->from($table->getName());
 		$result = $query->execute();
 		$count = $result->fetchColumn();
 		$result->closeCursor();
@@ -306,12 +307,30 @@ class ConvertType extends Command implements CompletionAwareInterface {
 		$query = $fromDB->getQueryBuilder();
 		$query->automaticTablePrefix(false);
 		$query->select('*')
-			->from($table)
+			->from($table->getName())
 			->setMaxResults($chunkSize);
 
+		try {
+			$orderColumns = $table->getPrimaryKeyColumns();
+		} catch (DBALException $e) {
+			$orderColumns = [];
+		}
+		foreach ($table->getIndexes() as $index) {
+			if ($index->isUnique()) {
+				$orderColumns = array_merge($orderColumns, $index->getUnquotedColumns());
+			}
+		}
+		$orderColumns = array_unique($orderColumns);
+
+		if (!empty($orderColumns)) {
+			foreach ($orderColumns as $column) {
+				$query->addOrderBy($column);
+			}
+		}
+
 		$insertQuery = $toDB->getQueryBuilder();
 		$insertQuery->automaticTablePrefix(false);
-		$insertQuery->insert($table);
+		$insertQuery->insert($table->getName());
 		$parametersCreated = false;
 
 		for ($chunk = 0; $chunk < $numChunks; $chunk++) {
@@ -329,7 +348,7 @@ class ConvertType extends Command implements CompletionAwareInterface {
 				}
 
 				foreach ($row as $key => $value) {
-					$type = $this->getColumnType($table, $key);
+					$type = $this->getColumnType($table->getName(), $key);
 					if ($type !== false) {
 						$insertQuery->setParameter($key, $value, $type);
 					} else {
@@ -365,11 +384,13 @@ class ConvertType extends Command implements CompletionAwareInterface {
 
 	protected function convertDB(Connection $fromDB, Connection $toDB, array $tables, InputInterface $input, OutputInterface $output) {
 		$this->config->setSystemValue('maintenance', true);
+		$schema = $fromDB->createSchema();
+
 		try {
 			// copy table rows
 			foreach($tables as $table) {
 				$output->writeln($table);
-				$this->copyTable($fromDB, $toDB, $table, $input, $output);
+				$this->copyTable($fromDB, $toDB, $schema->getTable($table), $input, $output);
 			}
 			if ($input->getArgument('type') === 'pgsql') {
 				$tools = new \OC\DB\PgSqlTools($this->config);
diff --git a/lib/private/DB/SchemaWrapper.php b/lib/private/DB/SchemaWrapper.php
index 0be45d8d3f..d686d7e63e 100644
--- a/lib/private/DB/SchemaWrapper.php
+++ b/lib/private/DB/SchemaWrapper.php
@@ -34,7 +34,7 @@ class SchemaWrapper {
 	protected $schema;
 
 	/** @var array */
-	protected $tablesToDelete;
+	protected $tablesToDelete = [];
 
 	/**
 	 * @param IDBConnection $connection