Re:Left to Right Programming
by balfirevic on Tuesday August 19, 2025 @06:15AM
(#44950019)
My impression was the parent poster was talking about order of operations like projection and selection, where you might more commonly write:
Π(σ(R)) instead of σ(Π(R))
and not about whether relational algebra uses prefix or postfix notation:
Π(σ(R)) vs. R > σ > Π
SQL's WHERE statement (and others) works totally differently from SELECT in that regard, so it doesn't make much sense to say that "SELECT comes first because relational algebra".
Π(σ(R)) instead of σ(Π(R))
and not about whether relational algebra uses prefix or postfix notation:
Π(σ(R)) vs. R > σ > Π
SQL's WHERE statement (and others) works totally differently from SELECT in that regard, so it doesn't make much sense to say that "SELECT comes first because relational algebra".