Speed/efficiency Of View Vs. Common/nested Table Expression In A Join
Mar 2, 2008
i have been trying to determine which is the most efficient, with regards to speed and efficiency, between a view and a common/nested table expression when used in a join.
i have a query which could be represented as index view or a common table expression, which will then be used to join against another table.
the indexed view will use indexes when performing the join. is there a way to make the common table expression faster than an indexed view?
I have a multi-tenant database where each row and each table has a 'TenantId' column. I have created a view which has joins on a CTE. The issue I'm having is that entity framework will do a SELECT * FROM MyView WHERE TenantId = 50 to limit the result set to the correct tenant. However it does not limit the CTE to the same TenantId so that result set is massive and makes my view extremely slow. In the included example you can see with the commented line what I need to filter on in the CTE but I am not sure how to get the sql plan executor to understand this or weather it's even possible.I have included a simplified view definition to demonstrate the issue...
ALTER VIEW MyView AS WITH ContactCTE AS( SELECT Col1, Col2, TenantId
I was studying Common Table expression in Sql server 2005. I have written the code Declare @PictureArray as varchar(200) Set @PictureArray = ''; with UserProfile_CTE(UserPicture) As( select @PictureArray = @PictureArray + '~' + PictureName from UserPicture where UserProfileID = 1102 select @PictureArray ) select * from UserProfile_CTE
But I am getting the error Incorrect syntax near '=' I am getting the error in the lineselect @PictureArray = @PictureArray + '~' + PictureName from UserPicture where UserProfileID = 1102 But I don't know the reason for this, Kindly advice Regards Karan
What is the SQL Server equivalent of DB2 common table expressions? Forexample,with gry(year,count) as(select floor(sem/10),count(distinct ssn)from gradesgroup by floor(sem/10))select year,sum(count) Head_Count from grygroup by yearhaving year >= 1980;N. ShamsundarUniversity of Houston
Hi, I'd like to perform a number of different operations on my Common Table expression but I seem to be limited to only one operation. For example I cannot both delete duplicate rows and then perform a select statement. I can only execute one of the statements referencing the common table expression.
What is wrong with my syntax?
;With OrderedTable
AS
(
select Row_number() OVER (partition BY SSNumber order by Department_Id desc ) AS ROWID,* from Employee
)
delete from OrderedTable where RowId != 1
SELECT COUNT(*),SSNumber FROM OrderedTable group by Department_Id order by count(*) desc
I want to do conditional processing depending on values in the rows of a CTE. For example, is the following kind of thing possible with a CTE?:
WITH Orders_CTE (TerritoryId, ContactId) AS ( SELECT TerritoryId, ContactId FROM Sales.SalesOrderHeader WHERE (ContactId < 200) ) IF Orders_CTE.TerritoryId > 3 BEGIN /* Do some processing here */ END ELSE BEGIN /* Do something else here */ END
When I try this, I get a syntax error near the keyword 'IF'
Any ideas? I know this kind of thing can be done with a cursor but wanted to keep with the times and avoid using one!
I tried to use WITH to factor out the shared star join portion from a sql statement as it's usually the most expensive part.
However, examing the execution plan shows that the WITH clause is merely a syntactic suger that will internally be plugged back as derived tables where the same star join is executed repeatedly.
Is the intermediate rowset produced by a WITH caluse ever shared during the query execution?
Using SQL against a DB2 table the 'with' key word is used todynamically create a temporary table with an SQL statement that isretained for the duration of that SQL statement.What is the equivalent to the SQL 'with' using TSQL? If there is notone, what is the TSQL solution to creating a temporary table that isassociated with an SQL statement? Examples would be appreciated.Thank you!!
I'm trying to have two common table expression in my stored procedure, but I'm receiving errors when executing it, I found that they can't exist side by side,once I removed 1 of them, the stored procedure executed successfully.
The following are the errors
Code:
Msg 156, Level 15, State 1, Procedure GetProductsByCategory, Line 27 Incorrect syntax near the keyword 'With'. Msg 319, Level 15, State 1, Procedure GetProductsByCategory, Line 27 Incorrect syntax near the keyword 'with'. If this statement is a common table expression or an xmlnamespaces clause, the previous statement must be terminated with a semicolon. Msg 319, Level 15, State 1, Procedure GetProductsByCategory, Line 33 Incorrect syntax near the keyword 'with'. If this statement is a common table expression or an xmlnamespaces clause, the previous statement must be terminated with a semicolon.
We are developing the web application using ASP.NET 2.0 using C# with Backend of SQL Server 2005.
Now we have one requirement with my client, Already our application live in ASP using MS Access Database. In Access Database our client already wrote the query, those query call the another query from same database. So I want to over take this functionality in SQL Server 2005.
In ASP Application, We call this query €œ081Stats€? from Record set.
This €˜081Stats€™ query call below sub query itself
Master Query: 081Stats
SELECT DISTINCTROW [08Applicants].school, [08Applicants].Applicants, [08Interviewed].Interviewed, [Interviewed]/[Applicants] AS [interviewed%], [08Accepted].Accepted, [Accepted]/[Applicants] AS [Accepted%], [08Dinged].Dinged, [Dinged]/[Applicants] AS [Dinged%], [08Waitlisted].Waitlisted, [Applicants]-[Accepted]-[Dinged] AS Alive, [08Matriculating].Matriculating, [Matriculating]/[Accepted] AS [Yield%] FROM ((((08Applicants LEFT JOIN 08Interviewed ON [08Applicants].school = [08Interviewed].school) LEFT JOIN 08Accepted ON [08Applicants].school = [08Accepted].school) LEFT JOIN 08Dinged ON [08Applicants].school = [08Dinged].school) LEFT JOIN 08Waitlisted ON [08Applicants].school = [08Waitlisted].school) LEFT JOIN 08Matriculating ON [08Applicants].school = [08Matriculating].school;
Sub Query 1: 08Accepted
SELECT statusTbl.school, Count(1) AS Accepted FROM statusTbl WHERE (((statusTbl.decision)=1) AND ((statusTbl.yearapp)="2008")) GROUP BY statusTbl.school ORDER BY Count(1) DESC;
Sub Query 2: 08Applicants
SELECT statusTbl.school, Count(1) AS Accepted FROM statusTbl WHERE (((statusTbl.decision)=1) AND ((statusTbl.yearapp)="2008")) GROUP BY statusTbl.school ORDER BY Count(1) DESC;
Sub Query 3: 08Dinged
SELECT statusTbl.school, Count(1) AS Dinged FROM statusTbl WHERE (((statusTbl.decision)=0) AND ((statusTbl.yearapp)="2008")) GROUP BY statusTbl.school ORDER BY Count(1) DESC;
Sub Query 4: 08Interviewed
SELECT statusTbl.school, Count(1) AS Interviewed FROM statusTbl WHERE (((statusTbl.interview)=True) AND ((statusTbl.yearapp)="2008")) GROUP BY statusTbl.school ORDER BY Count(1) DESC;
Sub Query 5: 08Matriculating
SELECT statusTbl.school, Count(1) AS Matriculating FROM statusTbl WHERE (((statusTbl.userdec)=True) AND ((statusTbl.yearapp)="2008")) GROUP BY statusTbl.school ORDER BY Count(1) DESC;
So now I got the solution from SQL Server 2005. I.e. Common Table Expressions, So I got the syntax and other functionality, Now my doubts is how do implement the CTE in SQL Server 2005, where can I store the CTE in SQL Server 2005.
How can I call that CTE from ASP.NET 2.0 using C#?
CTE is replacing the Stored Procedure and Views, because it is memory based object in SQL Server 2005.
How can I implement the CTE, where can I write the CTE and where can I store the CTE.
And how can I call the CTE from ASP.NET 2.0 using C#.
I have a stored procedure that return 0 or 1 row and 10 columns. In my subsequent queries I only need 1 column from those 10 columns. Is there any better way other than creating or declaring temp table and than making a select from that table.
So I am looking int CTE to execute stored procedure and than make a selection from CTE, but CTE does not allow me to execute stored procedure. Is there any other better way of acheiving this.
I'm using CTEs to try and get the totals of two different criteria queries that I want to group by Month depending on the associated Inquiry Date. Here is what I have right now;
Code: ;With CTE(total, InitDate) as ( SELECT count(Inquiry.ID), Inquiry.Date from Inquiry Inner Join Inquirer on Inquirer.ID = Inquiry.InquirerID_fk Left Join Transfer on Transfer.TransferInquiryID_fk = Inquiry.ID WHERE (Inquiry.Date >= '3/1/2012' AND Inquiry.Date <= '9/26/2012' AND Inquiry.Date IS NOT NULL) AND (Inquirer.Program = 'Res. Referral Coord.')AND TransferInquiryID_fk IS NULL Group By Inquiry.Date
[code]...
I get 170 for InitCount, but for TransCount I only get 19, not 26. I assume it is with my left outer join statement grouping but I am not sure how I would change this to get the proper counts. All I want to do is group the values together depending on the month they were done in.
What I am trying to do is count persons in buckets "non-recidivists" and "recidevists" based on how many bkg_nbr they have per STATE_NBR. If they have more than 1 bkg_nbr per STATE_NBR then put them in the "recdivists" bucket. If they only have a 1 to 1 then put them in the "non-recidivists" bucket.
What is the best approach to utilize a recursive CTE (Common Table Expression) to filter a resultset? The CTE function is used in all application queries to limit recursively the final resultset based on a provided hierarchical organization identifier. i.e. join from some point in the organization chart on down based on an organization id. I would prefer that the query could be run real-time. i.e. not having to persist the prediction portion of the results to a sql relational table and then limiting the persisted results based on the CTE function.
It appears that I can use a linked server to access the prediction queries directly from SQL Server (link below). I believe that I might also be able to deploy a CTE recursive function within a .net assembly to the Analysis Server but I doubt that recursive functionality is availalble without a linked SQL Server. Executing prediction queries from the relational server http://www.sqlserverdatamining.com/DMCommunity/TipsNTricks/3914.aspx
I guess that I had "Unit" (instead of "UnitForConc"), when I executed the sql code last time!!!??? How can I delete the old, wrong CTE that is already in the ChemDatabase of my SSMSE?
I have a table activity which show the activities of the site. An activity could be related with no other entity or it could be related with an account, or with a contact or with an opportunity. An opportunity and a contact could be also related with an account.
My problem is that I need to show the activity and the related account (if there is any) but because the relationship with an account could be done by different ways, I dont know how to do it without join the account table several times.
This is my current query:
SELECT AC.IdActividad, CU.idcuenta FROM Actividades AC LEFT JOIN Tareas TA ON TA.IdActividad = C.IdActividad LEFT JOIN ActividadesXCuenta AXC ON AC.IdActividad = AXC.IdActividad LEFT JOIN dbo.Cuentas CU ON axc.IdCuenta = CU.IdCuenta LEFT JOIN dbo.ActividadesXOportunidad axo ON AC.IdActividad = axo.IdActividad LEFT JOIN dbo.Oportunidades o ON axo.IdOportunidad = o.IdOportunidad LEFT JOIN dbo.Cuentas CU1 ON o.IdCuenta = CU.IdCuenta LEFT JOIN dbo.ActividadesXContacto axco ON AC.IdActividad = axco.IdActividad LEFT JOIN dbo.Contactos con ON axco.IdContacto = con.IdContacto LEFT JOIN dbo.Cuentas CU2 ON o.IdCuenta = CU.IdCuenta
As you see, I have the table Cuenta joined 3 times. That means that I need to put the ActivityID field 3 times but based on how the report was developed, I could not do that.
now i want to relate and join the table so that i can create a view with the following coloumns such as
start_date_time, dialed_digits, rounded_digits, cost, country, code,rate/min so can any body help me please i have tried outerjoin but it gave me rudundant data so please help me plz its urgent...
I'm new to this whole SQL Server 2005 thing as well as database design and I've read up on various ways I can integrate business constraints into my database. I'm not sure which way applies to me, but I could use a helping hand in the right direction.
A quick explanation of the various tables I'm dealing with: WBS - the Work Breakdown Structure, for example: A - Widget 1, AA - Widget 1 Subsystem 1, and etc. Impacts - the Risk or Opportunity impacts for the weights of a part/assembly. (See Assemblies have Impacts below) Allocations - the review of the product in question, say Widget 1, in terms of various weight totals, including all parts. Example - September allocation, Initial Demo allocation, etc. Mostly used for weight history and trending Parts - There are hundreds of Parts which will eventually lead to thousands. Each part has a WBS element. [Seems redundant, but parts are managed in-house, and WBS elements are cross-company and issued by the Government] Parts have Allocations - For weight history and trending (see Allocations). Example, Nut 17 can have a September 1st allocation, a September 5th allocation, etc. Assemblies - Parts are assemblies by themselves and can belong to multiple assemblies. Now, there can be multiple parts on a product, say, an unmanned ground vehicle (UGV), and so those parts can belong to a higher "assembly" [For example, there can be 3 Nut 17's (lower assembly) on Widget 1 Subsystem 2 (higher assembly) and 4 more on Widget 1 Subsystem 5, etc.]. What I'm concerned about is ensuring that the weight roll-ups are accurate for all of the assemblies. Assemblies have Impacts - There is a risk and opportunity impact setup modeled into this design to allow for a risk or opportunity to be marked on a per-assembly level. That's all this table represents.
A part is allocated a weight and then assigned to an assembly. The Assemblies table holds this hierarchical information - the lower assembly and the higher one, both of which are Parts entries in the [Parts have Allocations] table.
Therefore, to ensure proper weight roll ups in the [Parts have Allocations] table on a per part-basis, I would like to check for any inserts, updates, deletes on both the [Parts have Allocations] table as well as the [Assemblies] table and then re-calculate the weight roll up for every assembly. Now, I'm not sure if this is a huge performance hog, but I do need to keep all the information as up-to-date and as accurate as possible. As such, I'm not sure which method is even correct, although it seems an AFTER DML trigger is in order (from what I've gathered thus far). Keep in mind, this trigger needs to go through and check every WBS or Part and then go through and check all of it's associated assemblies and then ensure the weights are correct by re-summing the weights listed.
If you need the design or create script (table layout), please let me know.
If your prediction join is to a SQL datasource, you can easily write a SQL query which returns a nested table like:
SELECT Predict([Subcategories],2) as [Subcategories] FROM [SubcategoryAssociations] NATURAL PREDICTION JOIN (SELECT (SELECT 'Road Bikes' AS Subcategory UNION SELECT 'Jerseys' AS Subcategory ) AS Subcategories ) AS t
What about if your datasource is a cube? Is there some special MDX syntax similar to the SQL syntax above? Or do you have to utilize the SHAPE/APPEND syntax as follows?
SELECT t.*, $Cluster as ClusterName FROM [MyModel] PREDICTION JOIN SHAPE { select [Measures].[My Measure] on 0, [My Dimension].[My Attribute].[My Attribute].Members on 1 from MyCube } APPEND ( { select [Measures].[Another Measure] on 0, NON EMPTY [My Dimension].[My Attribute].[My Attribute].Members *[Product].[Product].[Product].Members on 1 from MyCube } RELATE [[My Dimension]].[My Attribute]].[My Attribute]].[MEMBER_CAPTION]]] TO [[My Dimension]].[My Attribute]].[My Attribute]].[MEMBER_CAPTION]]] ) AS [My Nested Table] AS t ON [MyModel].[Product].[Product] = t.[My Nested Table].[[Product]].[Product]].[Product]].[MEMBER_CAPTION]]]
Got a query taking too much time because of lack of cross columns MAX/MIN functions. Consider a similar example where a View is required to reflect distribution of Water among different towns each having four different levels of distribution reservoir tanks of different sizes:In this case the basic table has columns like:
Now suppose I need a query to distribute QuantityPurchased in the Four additional Columns computed on the basis depending on the sizes declared in the last four fields,in the same order of preference.For example: I have to use IIFs to check: whether the quantity purchased is less than Tank_A if yes then Qty Purchased otherwise Tank_A_Size itself for Tank_A_Filled
then again IIF but this time to check:
Whether the quantity purchased less Tank_A_Filled (Which again needs to be calculated as above) is less than Tank_B if yes then Tank_A_Filled (Which again needs to be calculated as above) otherwise Tank_B_Size itself for Tank_B_Filled
If I have three large tables to join together should I join the two that I know will cut the number of rows down a lot first and then join the 3rd table or does it make no difference (if I join the first and 3rd - which I know will be a large result set and then join the 2nd).
hi friends i am new to this forum and to the tech. also , i am reading a csv file and storing the data to the table of sql server 2005 database but the problem is i cannot join both the tables because both the tables doesnot have common cols and ther is no primary key field in any of the coloumn i have tried the sql query but i didn't got the desired output so could anyone help me please see the sql query of mine is like this:
SELECT dbo.table1.country, dbo.table1.code, dbo.table1.rate_min, dbo.table2.start_date_time, dbo.table2.rounded_dur, dbo.table2.cost, dbo.table2.dialed_digits FROM dbo.table1 INNER JOIN dbo.table2 ON dbo.table1.code = SUBSTRING(dbo.table2.dialed_digits, 1, 2) OR dbo.table1.code = SUBSTRING(dbo.table2.dialed_digits, 1, 3) OR dbo.table1.code = SUBSTRING(dbo.table2.dialed_digits, 1, 4) OR dbo.table1.code = SUBSTRING(dbo.table2.dialed_digits, 1, 5) OR dbo.table1.code = SUBSTRING(dbo.table2.dialed_digits, 1, 6)
I have a sql query that I am using to populate a datagrid. The problem is one of the tables is a month table. and the other tables are full of data. So there is no common column name to match using a inner join "on".
Select memberfrom NameListInner join Memberson (Left(Namelist.NameID,5) = Members.IDOR (left(namelist.SSN,9) = Members.ssnOR (Left(namelist.CustID,9) + '*01' = Members.CustID)wherenamelist.name <> ''How do I speed up a process like this? Can I create indexes on themembers table based on a functionLike an index based on the left(members.id,5)or should these statements go into the where clause?
I'm trying to sum a column in a report. in Most columns I can just wrap the row level expression with "Sum()" and it works. However, I have run into a few that give the following error. The Value expression for the text box ‘Textbox241’ specifies a scope that is not valid for a nested aggregate.  The scope must be the same name of the scope specified by the outer aggregate or the name of a group or data region that is contained in the scope specified by the outer aggregate.Here is my row level expression that works.
My question is fairly simple. When I join between two tables, I always use the ON syntax. For example:
SELECT
* FROM
Users
JOIN UserRoles
ON (Users.UserRoleId = UserRoles.UserRoleId)
No problems there. However, if I then decide to further filter the selection based on some trait of the UserRole, I have two options: I can add the condition as a WHERE statement, or I can add the condition within the ON block.
--Version 1:
SELECT
* FROM
Users
JOIN UserRoles
ON (Users.UserRoleId = UserRoles.UserRoleId) WHERE
UserRoles.Active = 'TRUE'
-- Version 2
SELECT
* FROM
Users
JOIN UserRoles
ON (Users.UserRoleId = UserRoles.UserRoleId
AND UserRoles.Active = 'TRUE')
So, the question is, which is faster/better, if either? The Query Analyzer shows the two queries have the exact same execution plan, which makes sense, since they're both joining the same tables. However, I'm wondering if adding the condition in the ON statement results in fewer rows the JOIN statement initially needs to join up, thus reducing the overall initial size of the results table before the WHERE conditions are applied.
So is there a difference, performance wise? I imagine that if Users had a thousand records, and UserRoles had 10 records, then the JOIN would create a cartesian product of the two tables, resulting in 10,000 records in the table before the WHERE conditions are applied. However, if only three of the UserRoles is set to Active, would that mean that the resulting table, before applying WHERE conditions, would only contain 3000 records?
I'm working on a "comments" section for our application suite. My thoughts are to have 1 Comments table, which is then linked to a comment Log table. For each section: Item, Group, Section, User, Package (these can all have comments on them) I will link them to the comments in a many to many relationship. Example: Comments Table-CommentID-UserID UserComments-UserID-CommentID User_Table-UserID.... Would doing that be more efficient than having 1 seperate comments table, and log table for each area I want to have comments?
I have came across a situation - When there are no indices on the tables and if we force SQL server to use the "Nested Loop" joins, the query becomes very slow. Since there are no indices then Nested loop join should not be used.
The background for this problem is - Analysis services is sending some query to SQL server while doing the cube processing. SQL server is using Nested loop joins even though there are no indices on any of the tables. Is there any way by which we can force the SQL server/Analysis services not to use Nested loop joins since there are no indices in any of the tables.
i'm running the following code on Ms SQL Server 2000, Query Analyzer to analyze the result of Nested Loop Join.
SET STATISTICS PROFILE ON GO SELECT pdN.ProductID, pdN.ProductName, spN.CompanyName, spN.ContactName FROM dbo.ProductsNew pdN INNER JOIN dbo.SuppliersNew spN ON pdN.SupplierId = spN.SupplierId GO
but the execution plan give me the following result :-
