Re: [Maria-discuss] Dynamic Columns ORM
Hi Daniel, Yes, I shall add remarks about indexes to the docs. I didn't have any purpose for "token" other than I needed a name for the strings that go in the SQL that refer to dynamic columns. Is there a problem with that particular word or do you think it would be better to do without any such name? You're spot on about computed columns. From my point of view, doing that amounts to adding the column to the schema. The column name appears in DDL and the corresponding attribute is therefore no longer ad hoc in the the application. The same point applies (in some imaginary future) to adding an index to a dynamic column without needing a computed column. If attributes represented in the application are to be truly fluid then their corresponding dynamic column cannot be indexed, at least not as I understand indexes in MySQL. Thanks for taking a look. Tom From: Daniel Black <daniel.black@openquery.com.au> Date: Saturday, May 23, 2015 at 1:27 AM To: Tom Worster <fsb@thefsb.org>, maria-discuss email list <maria-discuss@lists.launchpad.net> Subject: Re: [Maria-discuss] Dynamic Columns ORM They are generally good for blob like information that is generally retrieved in a query with some structure around name->value pairs. You mentioned (forum) that there isn't an index on these items so you'll get more row scanning on these if people search on a Dynamic attribute tokens (not sure why you are adding "token" to the language here). This limitation to be mentioned more in the documentation you've written. You could use computed columns to extract a variable to index if really needed but you'll need to ask why isn't it a column in its own right. https://mariadb.com/kb/en/mariadb/virtual-computed-columns/ Enhancing frameworks to expose database features is a good thing as they often get omitted in the reduction to the lowest common factor (mysql-5.0?) and sometimes the lowest common factor across db implementations (ansi SQL(?)). -- -- Daniel Black, Engineer @ Open Query (http://openquery.com.au) Remote expertise & maintenance for MySQL/MariaDB server environments.
----- On 24 May, 2015, at 1:41 AM, Tom Worster fsb@thefsb.org wrote:
Hi Daniel,
Yes, I shall add remarks about indexes to the docs.
I didn't have any purpose for "token" other than I needed a name for the strings that go in the SQL that refer to dynamic columns. Is there a problem with that particular word or do you think it would be better to do without any such name?
Just try to stay consistent which how mariadb/postgres call them rather than making up new terms. -- -- Daniel Black, Engineer @ Open Query (http://openquery.com.au) Remote expertise & maintenance for MySQL/MariaDB server environments.
participants (2)
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Daniel Black
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Tom Worster