July 5, 2013 at 4:00 am
I am trying an create the indexed view after joining two non related tables. Please correct me if my approach is wrong and add your thoughts for the issue I had mentioned below.
Syntax used for creating view
CREATE VIEW MyViewName
WITH SCHEMABINDING
AS
select field1, field 2 from tableOne (not the exact query)
FULL OUTER JOIN
select field1, field2 from tableTwo (not the exact query)
Syntax used for creating index on view
CREATE UNIQUE CLUSTERED INDEX ClusteredIndexTest
ON dbo.MyViewName(field1,field2)
Issue occurred while trying to create index
Msg 10109
Cannot create index on view "db.dbo.MyViewName" because it references derived table "tableOne" (defined by SELECT statement in FROM clause). Consider removing the reference to the derived table or not indexing the view.
July 5, 2013 at 4:25 am
Indexed views have some stringent requirements on what kind of view definition they can be created on. Derived tables are not allowed.
Have a look here for a complete list of what's not allowed:
http://msdn.microsoft.com/en-us/library/ms191432.aspx#Restrictions
July 5, 2013 at 4:41 am
Hi,
OUTER JOINs are not supported in Indexed views because rows can logically disappear under some update operations in the base tables.
Regards
IgorMi
Igor Micev,My blog: www.igormicev.com
July 5, 2013 at 6:39 am
Thanks for the reply.
Is there any way to tackle my scenario mentioned here.?
I need to combine (UNION) two non related derived tables and create an indexed view on top of that. Since UNION operation is not allowed under indexed views, I had tried to join then using OUTER JOIN. (I need data from both the non related derived tables unconditionally)
Please advice.
July 5, 2013 at 6:57 am
shyam00 (7/5/2013)
Thanks for the reply.Is there any way to tackle my scenario mentioned here.?
I need to combine (UNION) two non related derived tables and create an indexed view on top of that. Since UNION operation is not allowed under indexed views, I had tried to join then using OUTER JOIN. (I need data from both the non related derived tables unconditionally)
Please advice.
You're experiencing difficulty in creating an indexed view. Ok, so backtrack for a moment. View indexing is a performance measure. Somewhere, you're attempting to use these two tables, JOINed or UNIONed or whatever, in another query. Can you show an example of such a query, and if possible an actual execution plan? In the event that the indexed view you would ideally like to see is impossible to create, there may well be alternative means of accelerating the queries that the view would by used by.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden
July 5, 2013 at 12:57 pm
shyam00 (7/5/2013)
Thanks for the reply.Is there any way to tackle my scenario mentioned here.?
I need to combine (UNION) two non related derived tables and create an indexed view on top of that. Since UNION operation is not allowed under indexed views, I had tried to join then using OUTER JOIN. (I need data from both the non related derived tables unconditionally)
Please advice.
Hi,
Having an indexed view is almost same as having a table. As you have troubles creating it, why don't you think for another alternative?
- You can investigate on improving the performance of the queries using those selects you want to put in a view.
- You can create a separate table and add some work around to fill it appropriately.
Regards,
IgorMi
Igor Micev,My blog: www.igormicev.com
July 5, 2013 at 1:19 pm
shyam00 (7/5/2013)
Thanks for the reply.Is there any way to tackle my scenario mentioned here.?
I need to combine (UNION) two non related derived tables and create an indexed view on top of that. Since UNION operation is not allowed under indexed views, I had tried to join then using OUTER JOIN. (I need data from both the non related derived tables unconditionally)
Please advice.
And the advice is: start from the beginning. That is, why do you need this view? Why do you need it to be indexed?
[font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]
July 7, 2013 at 8:57 am
Currently I am building a search(filter) dash board application which is querying the underlying tables (OLTP) in MS SQL server 2008.
There are around 10 tables I need to query for getting the consolidated search results based on the filter condition. Most of the tables can be joined together, but there are some un-related tables as well.
There is performance trade off if I query each of these table and join them directly since number of concurrent users using this application will be more than 1000. Also some of the tables contain more than million records. That's why I didn't tried to use a stored procedure.
Based on this I though of using an Indexed view which contain all the fields required by search filter. And this indexed view getting refreshed using some trigger. Is there any other approach I can use in this scenario?
July 7, 2013 at 1:55 pm
Since the description you give is on a fairly high-level, it is difficult to give exact advice, but, no, from what you say I don't think indexed views is what you need.
To say more, we would need to see the tables (or preferrably some simplified layout of them) and how they are related. It sounds a little funny that you would search 10 entirely unrelated tables, so I assume that there is some form of relation between them.
What I can say is that indexing common search terms helps a log.
[font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]
July 7, 2013 at 10:41 pm
Out of those ten tables 9 are related. Only one table is non related one. I will give a sample layout soon.
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