Favourite performance tuning tricks [closed]

Answer 1

On all of my temp tables, I like to add unique constraints (where appropriate) to make indexes, and primary keys (almost always).

declare @temp table(
    RowID int not null identity(1,1) primary key,
    SomeUniqueColumn varchar(25) not null,
    SomeNotUniqueColumn varchar(50) null,
    unique(SomeUniqueColumn)
)