public Select::addExpression($expression, $alias = NULL, $arguments =

PostgreSQL implementation of \Drupal\Core\Database\Connection

public Schema::tableExists($table) Check

PostgreSQL implementation of

public Connection::query($query, array $args = array(), $options

protected Schema::resetTableInformation($table)

PostgreSQL implementation of

public Update::execute() Executes

protected Schema::_createKeySql($fields)

public Schema::fieldSetNoDefault($table, $field)