[Maria-discuss] virtual columns
I've read that MariaDB 5.2 will support virtual columns and I've read the virtual columns' specifications: http://forge.mysql.com/wiki/MySQL_virtual_columns_ref_manual I think there is a problem in that document. In CREATE TABLE and in ALTER TABLE commands you can create a virtual column. The syntax allows to specify that the column is STORED, if you wish. But it does not allow to specify that it's NOT STORED. This causes a little problem: one can not switch a STORED column to NOT STORED - one must to DROP and re-ADD the column. Also, I have a question: will virtual columns be able to use UDF's? Cheers, Federico
Hi! 5 февр. 2010, в 04:42, Federico Razzoli написал(а):
I've read that MariaDB 5.2 will support virtual columns and I've read the virtual columns' specifications:
http://forge.mysql.com/wiki/MySQL_virtual_columns_ref_manual
I think there is a problem in that document. In CREATE TABLE and in ALTER TABLE commands you can create a virtual column. The syntax allows to specify that the column is STORED, if you wish. But it does not allow to specify that it's NOT STORED. This causes a little problem: one can not switch a STORED column to NOT STORED - one must to DROP and re-ADD the column.
Our syntax is <type> [GENERATED ALWAYS] AS ( <expression> ) [VIRTUAL | PERSISENT] default is persistent. Syntax changed to be more compatible with MS SQL and Oracle
Also, I have a question: will virtual columns be able to use UDF's?
Any legal expression which can be calculated should be allowed.
5 февр. 2010, в 10:02, Oleksandr Byelkin написал(а): [skip]
Our syntax is <type> [GENERATED ALWAYS] AS ( <expression> ) [VIRTUAL | PERSISENT]
default is persistent. Syntax changed to be more compatible with MS SQL and Oracle
Sorry I forgot something: <type> [GENERATED ALWAYS] AS ( <expression> ) [VIRTUAL | PERSISENT] [UNIQUE] [UNIQUE KEY] [COMMENT <text>]
participants (2)
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Federico Razzoli
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Oleksandr Byelkin