MySQL: Altering ORDER BY

Please explain what this MySQL query is doing and how it can improve performance.  Also, is this a query that can be run once to improve performance or would I need to run this query regularly?
ALTER TABLE `sales` ORDER BY `sale_id`, `sale_time`, `sale_payment_status`, `sale_products_subtotal`, `sale_received`, `sale_refunded`, `sale_contact_id`, `sale_shipping_required`, `sale_shipping_standard`, `sale_shipping_charged`, `sale_fedex`, `sale_tax_method`, `sale_tax`, `sale_custom_credit_description`, `sale_custom_credit_amount`, `sale_payment_status2`, `sale_approval_number`, `sale_notes`, `sale_comments`, `sale_updated`, `sale_status`;

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skijAsked:
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HuaMin ChenProblem resolverCommented:
Alter table ... ORDER BY enables you to create the new table with the rows in a specific order. This option is useful primarily when you know that you are mostly to query the rows in a certain order most of the time. By using this option after major changes to the table, you might be able to get higher performance. In some cases, it might make sorting easier for MySQL if the table is in order by the column that you want to order it by later.

The table does not remain in the specified order after inserts and deletes.

ORDER BY syntax permits one or more column names to be specified for sorting, each of which optionally can be followed by ASC or DESC to indicate ascending or descending sort order, respectively. The default is ascending order. Only column names are permitted as sort criteria; arbitrary expressions are not permitted. This clause should be given last after any other clauses.

ORDER BY does not make sense for InnoDB tables because InnoDB always orders table rows according to the clustered index.
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ste5anSenior DeveloperCommented:
It sorts the table data by the given order. This is a one time sort process. Thus after further DML order is no longer guaranteed. It only works for tables without a clustered index, cause the clustered index is the physical table structure.

btw, what database engine do you use?
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MySQL Server

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