尝试创建有序SQL表时出错

Question

I'm trying to create a volatile table in SQL with an ORDER BY and I get an error.

CREATE VOLATILE TABLE orderd_dates AS
(SELECT * FROM date_table
ORDER BY id_date)
with data primary index (id_date) on commit preserve rows;

The error is: ORDER BY is not allowed in subqueries.

If I can't use order by, how can I create a volatile table that's ordered?

Answer 1

SQL tables are inherently unordered. You need to explicitly use an order by clause when querying the table, not when creating it.

Answer 2

You could add TOP 100 PERCENT to allow the ORDER BY, but the table would still be unordered, because a table is internally ordered by the Hash of the Primary Index. And if you use a NO PRIMARY INDEX TABLE and it would actually be stored in the specified order the optimizer wouldn't know about it.

The closest thing you can get is to PARTITION BY RANGE_N(id_date BETWEEN DATE '2000-01-01' AND DATE '2050-12-31' EACH INTERVAL '1' DAY :

CREATE VOLATILE TABLE orderd_dates AS
(SELECT * FROM date_table
)
WITH DATA 
PRIMARY INDEX (id_date)
PARTITION BY Range_N(id_date BETWEEN DATE '2000-01-01'
                                 AND DATE '2050-12-31' EACH INTERVAL '1' DAY)
ON COMMIT PRESERVE ROWS;