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MySQL

Can I create an INDEX to accelerate a SELECT MIN(IF(...)) in MySQL?

I have a table with a few columns, two of which are integers, one of which can be NULL in which case the other integer is to be used in my query.

CREATE TABLE my_table (col1 INTEGER NOT NULL, col2 INTEGER);

If `col2` is NULL, then use `col1`. As is, there is how my query looks like:

SELECT MIN(IF(col2, col2, col1)) AS smallest FROM my_table LIMIT 1;

In other words, I need to get the row with the smallest integer, but if one column is NULL, I want to use the other column value.

On a very small sample, the query is still very fast, but the real version is not unlikely to have thousands ...

MySQL CREATE USER features!

Today, I had to fix an installation of MySQL.

There were several problems, and I finally got it to work. Somehow, I had to run some commands manually to cleanly shutdown the cluster server and then re-run the configuration script with dpkg:

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    The dump command, under a Unix system, is used to dump the entire file system to another device. By default, the dump output device is a tape device (/dev/tape). Now a day, however, it is often used with other devices such as another file system (from one hard drive to another.)

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    C++ compiler from the GNU compiler suite. Compliant as much as possible to the C++ standard. Includes support of a complete standard library (STL).
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