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Re: Is the query order guaranteed using Btree indexes and no ORDER BY
Posted by: Ted Johnson
Date: May 29, 2019 04:41PM

Not surprised that the SQL standard states that. However in this example:

1. Rows are INSERTed into the two tables in the order of the index definitions.

2. Indexes are Btrees.

3. Tables contain millions of rows.

4. MySQL(or any database technology) is in a position to return the rows from a join of the two tables ordered by the index definitions and thereby not require an expensive ORDER BY sort given points 1 and 2 above.

Anyone know if the MySQL optimizer does this?

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Re: Is the query order guaranteed using Btree indexes and no ORDER BY
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May 29, 2019 04:41PM


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