Mysql internal Default sort

MySQL default sort:

https://forums.mysql.com/read.php?21,239471,239688#msg-239688

• depend on order when order by is missing.

• Always specify order by if you want a particular order – in some situations the engine can eliminate the order by because of how it does some and other step.

• GROUP by forces ORDER by. (This was a violation of the standard. It can be avoided by using the ORDER by NULL.)

SELECT * FROM tbl--This would do a "table scan". If The table has never had any deletes/replaces/updates, the records would happen to is in the insertion order, hence what You observed.

If you had do the same statement with an InnoDB table, they would has been delivered in PRIMARY KEY order, not INSERT O Rder. Again, this is a artifact of the underlying implementation, not something to depend on.

Https://stackoverflow.com/questions/8746519/sql-what-is-the-default-order-by-of-queries

Mysql internal Default sort