[thelist] MySQL oddness

Raoul Snyman raoul.snyman at saturnlaboratories.co.za
Wed Jan 30 03:22:01 CST 2008

Jeremy Weiss wrote:
> Quick question:
>> BTW, rule #1 of writing decent SQL: Never use SELECT *
>> This causes MySQL to first do a look up on all the columns of the table,
>> before then using them in the SELECT statement. When you specify the
>> columns, you firstly reduce the time it takes to execute the query and the
>> load on the MySQL server, and secondly you narrow the data down to only
>> that which you really need.
> Does this rule apply even if you do need every column in a table?

My answer would be "yes".

In the environment that I work in, fast queries are essential (I work
for one of the top online news sites in South Africa). So even if you
need every column in the table, a SELECT col1, col2, etc is faster than

While SELECT * is technically fine, I would say that it is not an SQL
best practice.

Raoul Snyman
Saturn Laboratories
e: raoul.snyman at saturnlaboratories.co.za
w: http://www.saturnlaboratories.co.za/
b: http://blog.saturnlaboratories.co.za/

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