public function up(Schema $schema)
{
$this->abortIf($this->connection->getDatabasePlatform()->getName() != 'postgresql', 'Migration can only be executed safely on "postgresql".');
$this->addSql('ALTER TABLE typo3_neos_domain_model_site ADD primarydomain VARCHAR(40) DEFAULT NULL');
$this->addSql('ALTER TABLE typo3_neos_domain_model_site ADD CONSTRAINT FK_1854B207B8872B4A FOREIGN KEY (primarydomain) REFERENCES typo3_neos_domain_model_domain (persistence_object_identifier) NOT DEFERRABLE INITIALLY IMMEDIATE');
$this->addSql('CREATE INDEX IDX_1854B207B8872B4A ON typo3_neos_domain_model_site (primarydomain)');
}