Dear All,
is there any difference performance wise using
select * from my_table
and
select mycol1,mycol2....mycoln from my_table
actually i've read from one article the there is big difference....
please clear my doubt...
thanks in advance
Vinod
Even you learn 1%, Learn it with 100% confidence.
Hello guys,
I would like to know if there is any meaningful difference in speed performance between using the DNS ("sql.server.com") or the IP address of the sql-server in the connection string.
The advantage of using DNS is that if there is any change in IP, I do not have to change the connection strings, but I do not want to loose speed because of the necessity to resolve the DNS.
Thanks for any help!
Regards,
Fabian
my favorit hoster is ASPnix : www.aspnix.com !
Hello Everyone,
Does anyone know if there is a performance difference between the new WITH clause t-sql and the subquery?
On a basic functionality level, they seem to perform the same function but I was wondering if there are any performance difference between the 2?
Thanks,
Joseph
I have one question what is performance difference between cluster index on numeric field or string field? I know that numeric is faster but why it is faster?
View 1 Replies View RelatedI have also posted this in microsoft.public.sqlserver.programming.
I have a query which, depending on where I run it from, will either take 10 milliseconds or 10 seconds.
The query works perfectly when run in SQL Server Management Studio... in my database of around 70,000 items it returns the results in around 10ms. It uses all my indexes and indexed views correctly.
However when I run the identical query from my ASP.NET application, it takes around 10 seconds... 1000 times longer.
Looking at it in Sql Server Profiler I can't see any difference in the query, except from ASP.NET it needs 62531 reads and from SSMS it needs only 318 reads. If I copy the slow running ASP.NET query from the profiler into SSMS, then it runs quick again. The results returned are the same.
I have provided more details of the query below, but I guess my real question is: What is the best way to debug this? I'm not an expert with SQL Server, so any pointers on where I should start looking to find the difference in how the query is being executed would be a great help.
The query is of the form:
WITH RowPost AS
(
SELECT
ROW_NUMBER() OVER(ORDER BY DateCreated DESC) AS Row,
ItemId,
Title,
....
FROM
Items_View WITH(NOEXPAND)
WHERE ItemX >= @minX AND ItemX <= @maxX AND ItemY >= @minY AND ItemY <= @maxY
)
SELECT
*,
(SELECT Count(*) FROM RowPost) AS [Count]
FROM RowPost
WHERE Row >= @minRow AND Row < @maxRow
Where Items_View is an indexed view, and WITH(NOEXPAND) is being used to force it to use the indexed view (this is optimal). The line beginning "SELECT Count(*)" is to get the total number of results (without having to run the inner query a second time).
This is running against SQL Server Developer Edition.
SQL 2000 Connection String:user id=MyUserName;password=MyPassword;initial catalog=MyDB;server=MyServer;Connect Timeout=30 This SELECT statement returns its 10 results nearly instantly:SELECT * FROM MyTableDitto from above, but completes in 30-40 seconds:SELECT * FROM [dbo].[MyTable]Ditto from above, but completes nearly instantly:
SELECT TOP 1000 * FROM [dbo].[MyTable] Obviously I have stopped using the [dbo] syntax in my SqlCommand's (SELECT's and EXECUTE's) but still would like to know why this is.vr, Rich
Hello, all, I started out thinking my problems were elsewhere but as Ihave worked through this I have isolated my problem, currently, as adifference between MSDE and SQL Express 2005 (I'll just call itExpress for simplicity).I have, to try to simplify things, put the exact same DB on twosystems, one running MSDE and one running Express. Both have 2 Ghzprocessors (one Intel, one AMD), both have a decent amount of RAM(Intel system has 1 GB, AMD system has 512 MB), and plenty of GB offree disk space. MSDE is running on the Intel system, Express isrunning on the AMD system. To keep things fair I use the exact sameDB's and query on both systems. The DB's were created on MSDE so Isp_detach_db'd them from MSDE and then sp_attach_db'd them to Express(this is how MS says to do a "side-by-side" upgrade, so it'sacceptable to do so). After fighting problems in performancedifferences in different situations I have narrowed the problem downto this:Executing a simple select statement with join clause on the databasesyields a difference in execution time that is quite great. Using theExpress Management program I can run the query against either system(MSDE or Express, the two systems are connected via crossover cable toeliminate any network problems/issues). When running the queryagainst the MSDE system (which is over the network) I consistently get<20 ms response times on the query. When running the query againstthe Express installation (which is in shared memory) I consistentlyget 700 ms or longer response times. Both times are for the TotalExecution Time.The query is simply this: select db1.* from db1.owner.tablename as db1inner join db2.owner.tablename as db2 on db1.pkey = db2.someid wheredb1.criteria = 3So, gimme all the columns from one table in one DB (local to theinstallation), matching the records in another DB (also local to theinstallation), where one field in the first db matches a field in thesecond db and where, in the first db, one column value = 3.The first table has a total record count of 630 records of which only12 match the where clause. The second table has a total record countof about 2,700 of which only 12 match up on the 12 out of 630.Even though the data is the same and I've done the detach and attach,and even done the sp_updatestats, the difference in execution time isremarkable, in a bad way.Checking the Execution Plan reveals that both queries have the samesteps, but, on the MSDE system the largest consumer in the process isthe Clustered Index Scan of the 630 record table (DB1 in my queryexample), using 85%. The next big consumer is a Clustered Index Seekagainst the other table (2,700 rows), using 15%.The Execution Plan against the Express system reveals basically theexact opposite: 27% going to the Clustered Index Scan of the 630record DB1, and 72% going to the Clustered Index Seek of the 2,700record DB2.I'm sorry to be stupid but I have this information but I don't knowwhat to do with it. The best that I can tell from this is that thisis the source of my problems. My problems are that on my currentsystems that my clients use the data is returned to them faster thanthey can click the mouse and that the new system (that is, when theychose (or are forced by attrition) to move to Vista and thus Express2005) the screen pop is like 1.5 seconds. This creates poor userexperience. Worse, one process I allow the users to do goes fromtaking 14-30 seconds to over 4 minutes (all on the same machine withthe same OS and version of my program, so it's not a machine or OS ormy app problem).Anyway, I hope someone can shed some light on this now that I've paredit down some.Thanks in advance.--HC
View 9 Replies View RelatedHi,
I created a CLR UDF that returns a large number of rows, when I run it from my VPC (XP, SQL Server Developer Edition and 1GB Memory) it takes approx 2 min and 30 secs to start displaying the rows (Using Management Studio), when I run the same query in our development server (Win 2003, SQL Server Enterprise Edition, 8 GB Memory and 8 Processors) it takes more than 15 min to start displaying the results, does anybody have an idea why is this happening?
Thanks in advance
Executing the stored procedure took 45 seconds. But copying the code to a query window and setting up the variables (instead of parameters), it took 7 seconds.
In the query window, most of the processing cost (86%) is right up front in a "Distinct Sort." But in exec stored procedure, the cost for this step is 11% and the significant costs are in later "Table Scans."
I don't know why SQL Server would choose different execution plans when the code is identical in each.
Any quick insights?
Many thanks.
Hi,
I'm having an issue with a query I'm running on Sql Server 2005. It's a semi-complex query involving an in-line table function and several left outer joins which are joined on to the results of the function call. Two of the left outer joins are then qualified in a where clause of the form where table.Col is not null; the idea is that the final result set contains data that has no match in those two tables.
The problem revolves around a where clause in the function and the last left outer join (ie, one of the ones qualified with where not null). When I alter the where clause of the function to further restrict the result set the function returns, the query times shoots up from 1 second to roughly 2-3 minutes. Note that the time the function takes to complete is not affected. The difference in time is purely down to what the query does with the results the function provides. Also note that the change to the where clause provides a subset of the original data; it does not add any more data (it actually restricts the original resultset by roughly 1000 rows).
I can bring the query speed back down again by removing the last left outer join - this join takes one of the columns from the function, and joins it to a small table - 924 rows. So it appears that this particular join is the cause of the issue, but only when using the resultset generated from the modified function query.
Now, as the thread title alludes, Sql Server 2000 and 2005 handle this differently, or appear to. When I execute this same query on a Sql 2000 machine, there's no apparent time differences, and the data that is returned is as expected. Does anyone have any suggestions as to what might be causing this and how I can fix it? I could simply return the larger resultset and use managed code to filter out the rows I don't want; however, I would like to get to the bottom of this, especially if it's going to effect future queries.
Cheers,
Chris
I have encountered a problem with a specific set of tables. The same select yields slightly differing execution plans in two different environments (instances). But the slight variation seems to contain a huge differences in stats. I don't know the significance of these stats. The two tables have the exact same indices.
This is the selcet statement:
SELECT 'xx' FROM DUKS.dbo.Profiler
WHERE DNA_Løbenummer IN
(SELECT DNA_Løbenummer FROM DUKS.dbo.Effektregister
WHERE Sagsnummer = '2015-00002')
SQL Server 2014 BI edition.
select * from sys.dm_os_performance_counters returns the object names prefixed with "SQLServer:" (e.g. SQLServer:Databases)
It was expected as in other editions also. Issue is that when we try to crate "SQLServer Performance Condition alert", object names in "Object" list comes without the prefix "SQLServer:" (e.g. Databases). Please see the attached snapshots.
Dear All,We have a database which contains many tables which have millions ofrecords. When We attach the database with MS SQL Server 2005 StandardEdition Server and run some queries (having joins, filters etc.) thenthey take very long time to execute while when We execute same querieson Enterprise Edition then they run 10 times faster than on standardedition.Our database does not use any features which are present in EnterpriseEdition and not present in Standard Edition. We want to know what arethe differences between Standard Edition and Enterprise Edition forperformance. Why should we go for Enterprise Edition when StandardEdition has all the features required.We are presently using evaluation versions of SQL Server 2005 Standardand Enterprise Editions.Thanks and regards,Nishant Sainihttp://www.simplyjava.com
View 23 Replies View RelatedHello,I have been searching and reading a lots of information on the microsoft website about the different version of SQL server, but still can not make my decision.In term of performance, is there a real big difference between the workgroup and the standard version? The workgroup is limited to 3 GB of RAM while the standard is unlimited, would that really change the performance if my server has 16Gb or RAM?The price difference is pretty substantial so if could only have to buy the workgroup , it would be better.One more question, regarding the type of licence, my server has 2 processors, could I avoid buying 2 licences and get the Server plus CAL instead. I am using this server to host 4 web-application running on SQL server. Each database is about 15 MB.Thanks in adavance for your advises.Arno
View 3 Replies View RelatedHi!
What is the difference in performance if I use a Temp-table or a local-table variable in a storedprocedure?
Why?
//Daniel
Is there a perf difference between:
create function dbo.zzz
returns uniqueidentifier
return '0000-0000-0000-00000000'
select dbo.zzz
vs.
se;ect '0000-0000-0000-00000000'
Thanks,
J
Question is in the subject.
Thanks in advance
-Jamie
Guys,
I've been asked to properly schedule some jobs on our system for a database following a full recovery model. I realized that the order for some of the jobs might matter and came up with the solution, which is described below.
Please let me know if this ordering makes sense and/or if you have any general comments/suggestions:
1. Backup all dbs [in case defragmentation messes something up]
2. Defragmentation [this will grow the transaction log]
3. Backup transaction log [backs up trans log and truncates inactive portion of it]
4. Shrink log file
Also, I've been previously suggested not to shrink the log file, unless absolutely necessary, as it is resource intensive. In my experience, however, this operation does not seem to be resource intensive at all. It took me 1 second to shrink the transaction log file from 25GB to 2GB.
Is it regrowing of the log file that will affect performance?
Also, if I do shrink the transaction log file, is there a suggested value to shrink it to - possibly a function of the database file size?
Thanks a lot
I have a table having 3 coulmns.
amnt1 amnt2 amnt3
100 200 230
200 170 120
290 188 299
800 170 120
i need to get max amount row wise like
amnt
230
200
299
800
Hi,
I have the following three tables :
Account (Id int, AccountName nvarchar(25))
Role (id int, Rights int)
AccountRole (AccountID, RoleID)
In Role table - Rights Column is a bit map where in each bit would refer to access to a method.
One account can be associated with multiple roles - AccountRole table is used for representing the N:N relation.
I want to develop a store procedure - which would return all AccountName and their Consolidated Rights.
Basically I want to do a BitWise OR operation for all the Rights in the Aggregation instead of the SUM as shown in the following statement.
SELECT Account.Name, SUM(Role.Rights) FROM Account WITH (NOLOCK)
JOIN RoleAccount ON RoleAccount.AccountID = Account.Id
JOIN Role ON RoleAccount.RoleId = Role.Id
GROUP BY Account.Name
Thanks,
Loonysan
My Table(collection) Structure consist of below:
TypeDate ItemAmount
REVENUE2007-04-01serv002***
REVENUE2007-04-01Serv004***
REVENUE2007-04-01serv005***
REVENUE2007-04-01AMC-***
ROYALTY2007-04-01serv002***
ROYALTY2007-04-01Serv004***
ROYALTY2007-04-01serv005***
ROYALTY2007-04-01AMC***
O/p should come as:
====================
Revenue:
MONTH AMC serv002 SER004 serv005
2007-04-01 *** **** *** ****
Royalty:
MONTH AMC serv002 SER004 serv005
2007-04-01 *** **** *** ****
Hi,
Need to write a query which would select data based on weekly wise based on the column Date.And week starts from Monday.
Hence would reqiure a function or a query which would select only those records which would fall under respective Weeks.
Help!!!
Regards,
Navneet
Dear All,
is there any way to generate daywise scripts in database? i mean all the transactions wether insert update or delete....
i need all the changes on that particular date(with in 24 hours)....
is there any procedure or function for this?
i've almost 1200 tables in that database.
note : due to replication is not possible for my scenario, i'm thinking in different ways to achieve my purpose.
this is my requirement
http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=96959
Vinod
Even you learn 1%, Learn it with 100% confidence.
Hi All,I want to give sequence no group wise, as follows:Section EmpCode-----------------------A 1001A 1003A 1009B 1023B 1030C 1044-----------------------I want to set sequence no. group wise like this for above data.Seq. Section EmpCode------------------------------1 A 10012 A 10033 A 10091 B 10232 B 10301 C 1044----------------------------Suggestion in this regard will be appreciatedThanks in Advance,T.S.Negi
View 3 Replies View RelatedI have a group and a subgroup in a report. in the subgroup there are repetitive rows. But i want to display them at only once within the subgroup. So I hide them. Now I want to have the sum of a field viz. "quantity" group wise, having the only single value of the subgroup. But problem is in the sum the values which are hidden also included. But i don't want them to include in the sum of the group.
Can anybody give the suggestions how to resolve the problem..
I am fighting with it from a long back but i am not able to solve the issue.. plz help me out..
location invoice no. date quantity item
delhi inv/del/1 1/1/2008 3 item-1
item-2
item-3
inv/del/2 2/1/2008 2 item-4
item-5
Location Total 5
This is what i want... for invoice inv/del/1 there are 3 items, i hide rest of two rows using "Hide Duplicates", But the group sum i.e. Location Total in the report is coming out as '13' as it includes the quantities of hidden rows also. But in actual I want '5'.
thanx you..
i want to know how to use order by clause in row wise
for example, suppose the rows is
10 20 30 40
so the output is should be
10
20
30
40
I have a table.
Highlight-------------
Id
Name
Detail
StartDate
EndDate
Priority
I want to make a query which returns 1 Highlight in the current date.
But remember I have already set the Hightlight Priority 1 to 5. And I want that Hight Priority rows select more times than Low Priority Rows.
Hi,
I have a requirement where I need to display the items category wise
I have 3 tables,
one stores category_id, parent_id and category_name
second table stored item_id,item_name and proce
3rd table stores category_id and item_id
I need to display the values like this
Category name, Item name
with first parent category ans ites items should be displayed and next sub category and its item
By category table with contain 2 levels of sub category
i.e Category1
Category11
Category111
any help with the query would be much appreciated, I wrote the query something like this....
select c.category_name,parent_id,item_name from category c,items i,Category_item ci where
ci.item_id=i.item_id and c.category_id=ci.category_id order by parent_id, category_nameBut it will display all parent category items then the sub category items I want to display like thiscategory1 items1category11 item11category1 item12category11 item111category11 item112 category2 item2
Thanks
How can I create a row wise trigger in MSSQL Server .
CREATE TRIGGER trigName ON tableName for
INSERT , UPDATE , DELETE
AS ...
For a multiple delete , I got only one trigger invocation .
But I need individual trigger calls for each row ...
How can I do this in t-sql ?
Is there any usage like FOR EACH ROW in Oracle ?
Is it possible through INSTEAD OF TRIGGER ?
Please help !!!!!!!!
Hi all,
i am using sql server 2005.
let me explain the scenario.
i am writing a function that return no of call a sales execituve done.
an executive can present n no of product to one customer but that call will be only one
my table record look like
empid custid product date and other field
em111 iimran aaaa 01-04-2008 ........
em111 iimran bbbb 01-04-2008 ........
em111 iimran cccc 01-04-2008 ........
em111 xxxxxx aaaa 01-04-2008 ........
em111 xxxxxx 2222 01-04-2008 ........
em111 iimran aaaa 02-04-2008 ........
em111 iimran bbbb 02-04-2008 ........
em111 iimran cccc 02-04-2008 ........
em111 xxxxxx aaaa 02-04-2008 ........
em111 xxxxxx 2222 02-04-2008 ........
Now if i select total no of call it should give me four call
also i am getting this through this query
select dcr_date , cust_id from vwdcrdtl where emp_id = @empcode and dcr_date between @stdate and @enddate group by dcr_date , dcr_cust_id
this query correctly return 4 rowcount(which i am gerring though @@rowcount) but i want this rowcount to return from function
i assinged this to rowcount to int veriable but this giving me error .
i would like to know how can i get count of these records
Please Help
I have the employees and department tables(structure below).
Write a sql to get the department name,employee earning maximum salary,employee earning minimum salary for each department
result set:
dname |max_salaried_employee|min_salaried_employee
------------------------------------------------------
Accounts | Blakes | Miller
HR | King | James
Structure :
create table dept(
deptno number(2,0),
dname varchar2(14),
loc varchar2(13),
constraint pk_dept primary key (deptno)
[Code] .....
Hi Folks,
Please help me in writing a query. I need to get current strength of employee's, monthwise (till each month).
Table Structure
----------------
Employee_Master
ED_EmpId ED_DOJ ED_Name
-------- ------- ---------
2006-01-02 SRINIVASA
2006-01-02 KAVITA
2006-01-02 VIVEK
2006-02-20 CHANDRA
2006-02-25 PARIMAL
2006-02-30 SATISH
........
2007-01-10SANJEEV SHARMA
2007-01-14 JITENDRA PRATAP SINGH
2007-03-15 SANDEEP
2007-03-02 SUNIL KUMAR SHARMA
I require the data in the below format..
For the year '2007-2008'
Month Count
----- -----
April(07) 10
May . 10
June . 10
July . 10
August . 10
Sept 10
Oct 10
Nov 10
Dec 10
Jan (08) 10
Feb . 10
March . 10
Thanks.
Hi,
I need to get the groupwise distinct count .
For eg. Lets assume we have group as Category and under this there are two childs Category1 and Category2.
I need the distinct count under Category1 and Category2 separately with the count resetting after Category1 and Category2.
Any help will be greatly appreciated.
Regards,
Ravi