The Order By clause is supported, with the following Entry SQL level restrictions:
An integer sort key is not allowed.
The COLLATE clause is not supported.
A LIMIT clause or a default ORDER BY limit for result sets is required.
Default ORDER BY Limit
Impala will not return result sets for statements containing an order by clause unless a limit clause is included or a default limit is specified for result sets. A default limit can be set in the server; however, this limits the result sets for all queries, not just statements containing the ORDER BY clause.
The driver can work around these limitations by using the Default Order By Limit connection option.
where:
x
is a positive integer that represents maximum number of rows returned.
If set to x, the number of rows returned by a SQL statement containing an ORDER BY clause are limited to the specified number of rows for the session. To override this value, specify a new value in a LIMIT clause in the statement that is being executed.
If set to -1(disabled), there is no default limit the number of rows returned by a statement containing an ORDER BY clause. The application must limit the number of rows returned by SQL statements that contain an ORDER BY clause, or Impala will return an error.
An integer sort key is not allowed.