Click here to monitor SSC
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Local Temporary Tables and Table Variables


Local Temporary Tables and Table Variables

Author
Message
GilaMonster
GilaMonster
SSC-Forever
SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)

Group: General Forum Members
Points: 47427 Visits: 44405
Yes, I did.


Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


SQLRNNR
SQLRNNR
SSC-Insane
SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)

Group: General Forum Members
Points: 21151 Visits: 18259
Thanks. That is what I thought.



Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw

smeet.sinha
smeet.sinha
Grasshopper
Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)Grasshopper (15 reputation)

Group: General Forum Members
Points: 15 Visits: 105
One more major diff.


You can not use temp tables in UDF
But can use table variables in UDF....
Jeff Moden
Jeff Moden
SSC-Forever
SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)SSC-Forever (45K reputation)

Group: General Forum Members
Points: 45443 Visits: 39944
True enough. You should also mention that most UDFs aren't necessary either. :-)

--Jeff Moden

RBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.
Although they tell us that they want it real bad, our primary goal is to ensure that we dont actually give it to them that way.
Although change is inevitable, change for the better is not.
Just because you can do something in PowerShell, doesnt mean you should. Wink

Helpful Links:
How to post code problems
How to post performance problems
Forum FAQs
Graham_Day
Graham_Day
SSC-Addicted
SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)SSC-Addicted (467 reputation)

Group: General Forum Members
Points: 467 Visits: 283
GilaMonster (8/31/2008)
Very nice.

Just one small thing. You say that for data storage, temp tables are in TempDB and table variables are in memory and tempDB. I may be misunderstanding what you mean there, but temp tables are also memory resident unless it becomes necessary to write them to disk (memory pressure, too large a table)


Also, the Appendix states that table variables are held in memory and temporary tables are held in tempdb. Whilst usually correct*, it is also the case that both are physically created in tempdb, as can be demonstrated by running the following code on a SQL Server which has no other activity occurring (runs on SQL 2000, 2005 and 2008):

-- make a list of all of the user tables currently active in the
-- TempDB database
if object_id('tempdb..#tempTables') isnot null droptable #tempTables
select name into #tempTables from tempdb..sysobjectswhere type ='U'
-- prove that even this new temporary table is in the list.
-- Note the suffix at the end of it to uniquely identify the table across sessions.
select * from #tempTables where name like '#tempTables%'
GO
-- create a table variable
declare@MyTableVariable table (RowID int)
-- show all of the new user tables in the TempDB database.
select name from tempdb..sysobjects
where type ='U' and name notin (select name from #tempTables)
GO



* According to KB305977, a table variable can hold more data than could fit into memory.
http://support.microsoft.com/default.aspx?scid=kb;en-us;305977&Product=sql2k
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search