SQL Server Performance Forum – Threads Archive

Which is better Table variable or Union?

I have a stored procedure expecting a $delimited input called type. For example type = ‘0$2$4$8$16$32’ This sp has to fetch data from different tables based on the type and return in a single select. Should use table variables or should I go for a Union and IN Clause. First Scenario First I break the type variable and insert a record into a table variable InputType.
Take another table variable OutputData — get data for all types except 32
Insert into OutputData
Select * from DATA1 t1 INNER JOIN InputType t2
on t1.type = t2.type and t1.type <> 32 — get data for type 32
Insert into OutputData
Select * from DATA2 t3 INNER JOIN InputType t2
on t3.type = t2.type and t3.type = 32 Select * from OutputData Second Scenario I replace the ‘$’ with a ‘,’ and also remove a particular type 32.
— so @type will be something like ‘0,2,4,8,16’
Create a dynamic query EXEC (‘Select * from DATA1 t1 INNER JOIN InputType t2
on t1.type = t2.type and t1.type IN @type
UNION
Select * from DATA2 t3 INNER JOIN InputType t2
on t3.type = t2.type and t3.type = 32′) What do you suggest which one will be faster or can you provide a better way to handle the same.

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See Erland Sommarskog’s web site for an article on this very topic

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