SQL WHERE Clause Optimization -


suppose have following 3 types:

  • type1
  • type2
  • type3

from optimization standpoint (ignoring maintainabilty; know first option less break if new type added); more efficient write clause this:

where p.typeid in (type1, type2)

or

where p.typeid <> type3

your second option:

where p.typeid <> type3

will more efficient write, uses fewer characters, unless you're on ipad in case it's quite slow < , > chars!

in terms of execution it'll faster execute. has less work single comparison required, whichever way optimise <> going faster in 2 elements.


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