Re:Why SELECT * is bad for SQL performance (2020)
by astura on Monday February 15, 2021 @08:36AM
(#26142590)
Ummm... you seem very confused... The "select" part of the query solely filters on columns, not rows. You are talking about filtering on rows.
Beyond that, when you are looking for anomalous conditions you don't say "get me all records," because how you going to pick out something that doesn't look right out of five million items? When you are looking for anomalous conditions you say "get me all records that are NOT in the form I am expecting." Then you add constraints, foreign keys, etc so it doesn't happen again.
Beyond that, when you are looking for anomalous conditions you don't say "get me all records," because how you going to pick out something that doesn't look right out of five million items? When you are looking for anomalous conditions you say "get me all records that are NOT in the form I am expecting." Then you add constraints, foreign keys, etc so it doesn't happen again.