Classes/Console/Database/Schema/SchemaUpdate.php
public function getSafeUpdates()
    {
        $sqlStatements = $this->sqlReader->getCreateTableStatementArray($this->sqlReader->getTablesDefinitionString());
        $addCreateChange = $this->schemaMigrator->getUpdateSuggestions($sqlStatements);

        // Aggregate the per-connection statements into one flat array
        return array_merge_recursive(...array_values($addCreateChange));
    }
public function getSafeUpdates()
    {
        $sqlStatements = $this->sqlReader->getCreateTableStatementArray($this->sqlReader->getTablesDefinitionString());
        $addCreateChange = $this->schemaMigrator->getUpdateSuggestions($sqlStatements);

        // Aggregate the per-connection statements into one flat array
        return array_merge_recursive(...array_values($addCreateChange));
    }
Get all schema updates that are considered (relatively) safe

@return array