There are _tons_ of SQL queries that involve redundant and/or stupid things. A lot of them come from autogenerated queries where the user has nearly zero contro

There are _tons_ of SQL queries that involve redundant and/or stupid things. A lot of them come from autogenerated queries where the user has nearly zero control over the actual SQL. An optimizer's job is to optimize that away, not reject them as “please be more efficient”. They are legal queries. All legal queries should be accepted and executed, no matter how silly one may consider them. As an aside, C compilers generally try to give warnings (not errors) on things like this, but need tons of heuristics to distinguish the “obviously wrong” cases from the “not obviously wrong” cases (e.g., those that arose from inlining and/or constant folding and/or preprocessor expansion and/or dead code removal).