And then salle threw out “.

Weitzel: I would have expected some kind of predictability which could be used for optimizing the query

Keiter: Scott0_: many DBAs think they can write “faster” sql, but the engine often can rewrite it into something faster. But sometimes it fails

Correl: Scott0_: you’ll never know how it will evaluate the conditions even after you use the explain :

Correl: Scott0_: Because it does not matter how they will be evaluated

Keiter: Scott0_: the point it – don’t try to outsmart the MySQL engine

Correl: Scott0_: Just like it does not matter at all if you are evaluating these using pen an paper.

Keiter: Scott0_: you’ll waste your time, and in the few cases where the engine is wrong, you can work around it.

Keiter: Scott0_: using EXPLAIN, of course.

Correl: Scott0_: You can do it from left to right or right to left or any other way, but as long as you follow the precedence rules the end result will be always the same

Keiter: Brittman: well, if you’re at Scott0_’s skill level, anyway

Brittman: I am quite terrified of 5.7 opt hints

Correl: Scott0_: Question: Does it matter if you write: x = 2 + 1; or x = 1 + 2; ?

Keiter: Scott0_: note that I’m not saying you’re not good – just seem a bit rusty

Brittman: I wonder how many oracle apps ported to mysql with similar hints in place will just break

Correl: Scott0_: Then why did we spend so much time arguing about literally the same? :

Okelberry: Nor does it matter if its written as 2 = x -1

Keiter: Brittman: I think I have too much faith in MySQL

Correl: Scott0_: You are wrong about last one in context of SQL you know :

Stagger: X still sovles for the same

Brittman: Keiter:

Liebig: Ahh, was just missing a ‘;’ ok works nice now

Correl: Scott0_: WHERE x = 2 + 1; is fine whereas WHERE x – 1 = 2; can be disaster

Correl: Scott0_: The latter can’t use index

Desruisseaux: I guess I was thinking mysqls engine was simpler

Correl: Scott0_: The result is the same, but the efficiency is different

Rago: Jesus its been an hour

Brittman: Yay broken logical backups during restore

Keiter: Scott0_: it’s OK, we made progress. You learned that the order doesn’t matter in the WHERE clause.

Correl: Scott0_: Here we go:

Hledik: Keiter: but precedence does even though precedence is a form of order. :

Keiter: Scott0_: it isn’t. You can work on that ***umption later, too.

Asato: Its not an ***umption, it’s a definition of the word in the english language

Keiter: Scott0_: it doesn’t apply to SQL.

Vipperman: Maybe not in mysql world

Correl: Scott0_: Even better example with higher cardinality:

Correl: Scott0_: Precedence in SQL is not an order. Precedence in programming languages is not an order.

Correl: Scott0_: English language doesn’t matter much when talking about terminology.

Correl: Scott0_: “operator” is a person in English in all its dictionary meaning. Not in SQL

Wygle: Https://

Crispen: Lol, they use the word order quite a bit there

Correl: Scott0_: Notably they don’t use it in a way you use it

Meiss: I said order of operations

Correl: Scott0_: Do you have MySQL related question?

Neubacher: I thought we were talking about precedence in mysql

Keiter: I think we’ve covered the subject more than adequately.

Correl: Scott0_: Do you have MySQL related question?

Strahm: And then salle threw out ” Precedence in programming languages is not an order.”