Dynamic Cursor Versus Forward Only Cursor Gives Poor Performance
Jul 20, 2005
Hello,
I have a test database with table A containing 10,000 rows and a table
B containing 100,000 rows. Rows in B are "children" of rows in A -
each row in A has 10 related rows in B (ie. B has a foreign key to A).
Using ODBC I am executing the following loop 10,000 times, expressed
below in pseudo-code:
"select * from A order by a_pk option (fast 1)"
"fetch from A result set"
"select * from B where where fk_to_a = 'xxx' order by b_pk option
(fast 1)"
"fetch from B result set" repeated 10 times
In the above psueod-code 'xxx' is the primary key of the current A
row. NOTE: it is not a mistake that we are repeatedly doing the A
query and retrieving only the first row.
When the queries use fast-forward-only cursors this takes about 2.5
minutes. When the queries use dynamic cursors this takes about 1 hour.
Does anyone know why the dynamic cursor is killing performance?
Because of the SQL Server ODBC driver it is not possible to have
nested/multiple fast-forward-only cursors, hence I need to explore
other alternatives.
I can only assume that a different query plan is getting constructed
for the dynamic cursor case versus the fast forward only cursor, but I
have no way of finding out what that query plan is.
I have always been told that Cursors create a lot of overhead and consume a lot of system resources. Is it faster to store the data in a temp table and loop through it by using Select Top 1 and Delete statements or by using a static, Forward-Only Cursor? Both ways store the data in TempDB, but doesn't the While Loop statement generate more IO's than the Cursor? In theory, I am thinking that the Cursor is better. Any info will be appreciated.
I know this question has been asked. And the usual answer is don't usecursors or any other looping method. Instead, try to find a solutionthat uses set-based queries.But this brings up several questions / senarios:* I created several stored procedures that take parameters and insertsthe data into the appropriate tables. This was done for easy access/usefrom client side apps (i.e. web-based).Proper development tactics says to try and do "code reuse". So, if Ialready have stored procs that do my logic, should I be writing asecond way of handling the data? If I ever need to change the way thedata is handled, I now have to make the same change in two (or more)places.* Different data from the same row needs to be inserted into multipletables. "Common sense" (maybe "gut instinct" is better) says to handleeach row as a "unit". Seems weird to process the entire set for onetable, then to process the entire set AGAIN for another table, and thenYET AGAIN for a third table, and so on.* Exception handling. Set based processing means that if one row failsthe entire set fails. Looping through allows you to fail a row butallow everything else to be processed properly. It also allows you togather statistics. (How many failed, how many worked, how many wereskipped, etc.)?? Good idea ?? The alternative is to create a temporary table (sandboxor workspace type thing), copy the data to there along with "status" or"valdation" columns, run through the set many times over looking forany rows that may fail, marking them as such, and then at the end onlydealing with those rows which "passed" the testing. Of course, in orderfor this to work you must know (and duplicate) all constraints so youknow what to look for in your testing.
STATIC Defines a cursor that makes a temporary copy of the data to be used by the cursor. All requests to the cursor are answered from this temporary table in tempdb; therefore, modifications made to base tables are not reflected in the data returned by fetches made to this cursor, and this cursor does not allow modifications
It say's that modifications is not allowed in the static cursor. I have a questions regarding that
Static Cursor declare ll cursor global static            for select name, salary from ag  open ll             fetch from ll               while @@FETCH_STATUS=0               fetch from ll                update ag set salary=200 where 1=1    close ll deallocate ll
In "AG" table, "SALARY" was 100 for all the entries. When I run the Cursor, it showed the salary value as "100" correctly.After the cursor was closed, I run the query select * from AG.But the result had updated to salary 200 as given in the cursor. file says modifications is not allowed in the static cursor.But I am able to update the data using static cursor.
I'm trying to implement a sp_MSforeachsp howvever when I call sp_MSforeach_worker I get the following error can you please explain this problem to me so I can over come the issue.
Msg 16958, Level 16, State 3, Procedure sp_MSforeach_worker, Line 31
Could not complete cursor operation because the set options have changed since the cursor was declared.
Msg 16958, Level 16, State 3, Procedure sp_MSforeach_worker, Line 32
Could not complete cursor operation because the set options have changed since the cursor was declared.
Msg 16917, Level 16, State 1, Procedure sp_MSforeach_worker, Line 153
Cursor is not open.
here is the stored procedure:
Alter PROCEDURE [dbo].[sp_MSforeachsp]
@command1 nvarchar(2000)
, @replacechar nchar(1) = N'?'
, @command2 nvarchar(2000) = null
, @command3 nvarchar(2000) = null
, @whereand nvarchar(2000) = null
, @precommand nvarchar(2000) = null
, @postcommand nvarchar(2000) = null
AS
/* This procedure belongs in the "master" database so it is acessible to all databases */
/* This proc returns one or more rows for each stored procedure */
/* @precommand and @postcommand may be used to force a single result set via a temp table. */
declare @retval int
if (@precommand is not null) EXECUTE(@precommand)
/* Create the select */
EXECUTE(N'declare hCForEachTable cursor global for
I need to pass a list of values into a cursor as such...
DECLARE @group_SQL varchar(255)
SET @group_SQL = 'SELECT group_id FROM groups where group_id in (' + @group_id + ')'
DECLARE groupContact_import_cursor CURSOR FOR EXEC(@group_SQL) OPEN groupContact_import_cursor FETCH NEXT FROM groupContact_import_cursor INTO @group_id WHILE (@@FETCH_STATUS = 0) BEGIN insert into groupContacts (group_id, contact_id) values (@group_id, @new_cid) FETCH NEXT FROM groupContact_import_cursor INTO @group_id END CLOSE groupContact_import_cursor DEALLOCATE groupContact_import_cursor
But MS SQL doesn't seem to like the FOR EXEC(@group_SQL). Can someone shed some light?
I am trying to use a dynamic cursor in a stored procedure: The code looks like this :
/************************************************** *** set @sFormula = 'Monthlyformula' set @sStartDate = '02/01/2004' set @sEndDate = '02/01/2004'
exec('DECLARE APPGRIDROWS_METRICS CURSOR FOR select populateid From appgridrows where histdisplaygrid = 3 And '+ @sFormula +' Is Null and exists (SELECT 1 From PAYROLL_DATA_PERIOD as h Where h.id=1 and h.populateid=appgridrows.populateid and h.StartDate between '+ @sStartDate +' and '+ @sEndDate +')' ) /************************************************** ***
And this is what it is interpreting
select populateid From appgridrows where histdisplaygrid = 3 And Monthlyformula Is Null and exists (SELECT 1 From PAYROLL_DATA_PERIOD as h Where h.id=1 and h.populateid=appgridrows.populateid and h.StartDate between 02/01/2004 and 02/01/2004)
My problem is Is there anyway that I can put the quotes before those dates('02/01/2004') so that my cursor has some records returned
I have a situation where the SQL for my cursor MUST be assembled in a buffer, but I cannot get the cursor declaration to accept my buffer as the SQL statement.
these attempts did not work:
DECLARE crsCursor CURSOR FOR @vchrSQL DECLARE crsCursor CURSOR FOR (@vchrSQL)
Does anybody know if you definitely can or definitely cannot use dynamic SQL with cursors?
I am trying to do dynamic Select for Cursor. The dynamic would be like this: IF CONDITION1 IS TRUE: SELECT CustomerTenderID, CustomerSiteID, ContractPeriod, SupplierID FROM dbo.tnd_TenderSiteRateConsumptionView WHERE CustomerTenderID = @CustomerTenderID IF CONDITION2 IS TRUE: SELECT CustomerTenderID, CustomerSiteID, ContractPeriod, SupplierID FROM dbo.tnd_TenderSiteRateConsumptionView WHERE CustomerTenderID = @CustomerTenderID AND CustomerSiteID = @CustomerSiteID
etc etc
Here's the cursor
DECLARE RateList CURSOR FOR SELECT CustomerTenderID, CustomerSiteID, ContractPeriod, SupplierID FROM dbo.tnd_TenderSiteRateConsumptionView WHERE (BASED ON CONDITION) ORDER BY CustomerTenderID, CustomerSiteID, SupplierID, ContractPeriod
OPEN RateList FETCH NEXT FROM RateList INTO@CustomerTenderID, @ReturnedCustomerSiteID, @ReturnedContractPeriod, @ReturnedSupplierID WHILE @@FETCH_STATUS = 0 BEGIN SET @rowNum = @rowNum + 1
-- DO SOME FUNKY STUFF
FETCH NEXT FROM RateList INTO@CustomerTenderID, @ReturnedCustomerSiteID, @ReturnedContractPeriod, @ReturnedSupplierID
Help please,Have a situation when converting from Oracle SP's to SQL SP's. The oldoracle cursor was roughly as followsCURSOR cur_rsStock ISselect*from(select StockRowId, CategoryIdfromSTOCKDISPOSABLEwhereSTOCKDEFID=numDefIdORDER BYSTOCKROWID)whereROWNUM <= numQuantity;The closest I can get in MS SQL is as follows :declare cur_rsStockCURSOR forselect top @numQuantityStockRowId, CategoryIdfromSTOCKDISPOSABLEwhereSTOCKDEFID=numDefIdORDER BYSTOCKROWIDBut, SQL doesn't allow variables next to top. I know I can assign the wholeselect statement to a string and use exec to exec the string to get arecordset but how can I point a cursor to receive its output?i.e.set @strSQl = select top ' + @numQuantity + ' StockRowId, CategoryId.......exec @strSQLbut how do I dodeclare cur_rsStockset cur_rsStock = ( exec @strSQL)Flapper
Hi Everybody,I have a probs with dynamic generation.I am writing the probs======================================create proc testasdeclare @query varchar(500)set @query = 'select * from table'----------------------------------------------declare mycur Cursor for Select * from table |open mycur |----------------------------------------------but instate of above block how can I dynamically generate this query?---------------------------------------declare mycur Cursor for exec (@query) |---------------------------------------Or tell me the way.RegardsArijit Chatterjee
"Cursor provide row-by-row level processing and it will store the result sets in 'TEMPDB' database".
(Because of this) or (By using Cursor in Triggers or Stored Procedures) the performance will increase or performance will come down?. I am thankful if I get a good reason for this?
I have a stored procedure below that loops through a table and updates another table. I used to do this client side in vb but was hoping for better performance when doing everything server side.
Question;
Am I doing something wrng since the query is that slow.? Why is cursors so bad ?
Thanks
David
ALTER PROCEDURE usp_setinternational
AS
Declare @acnt_no int
declare @cntry_code varchar(10)
declare @counter int
declare @error int
declare MyC cursor
Local
for
SELECT ACNT_NO, COUNTRY_CODE FROM INTNL_ACNT
open MyC
fetch next from MyC into @acnt_no,@cntry_code
select @counter = 1
while @@fetch_status = 0
begin
update xform2 set
address_type='m'
where acnt_no = @acnt_no
update addr set delivery='m',cntry_cde= @cntry_code
where addr_id in (select addr_id from acnt_addr where acnt_no = @acnt_no)
hi friends i am using a cursors to fetch data row by row , but the main problem is it takes a very big time span to execute can anybody help me out to replace cursor with some other method or trick so that i can make it perform fast... see my query is like this:
--update cdr set destinationid = null
DECLARE @CDRID BIGINT;
DECLARE @CodeDestID BIGINT;
DECLARE @TempCodeDestID BIGINT;
DECLARE @CtryCode VARCHAR(20);
DECLARE @MATCH INT;
DECLARE @dialed_digits NVARCHAR(50); DECLARE @FormattedNbr VARCHAR(50); DECLARE @CountryCode VARCHAR(2); DECLARE CDR_cursor CURSOR FOR SELECT CDRID, dialed_digits FROM mydata.dbo.CDR WHERE DestinationID IS NULL OPEN CDR_cursor
FETCH NEXT FROM CDR_cursor INTO @CDRID, @dialed_digits
WHILE @@FETCH_STATUS = 0
BEGIN
SET @FormattedNbr = replace(LTRIM(RTRIM(@dialed_digits)), '"', '');
SET @CountryCode = substring(@FormattedNbr, 0, 3);
SET @CodeDestID = null;
SET @MATCH = 0;
DECLARE Dest_cursor CURSOR FOR SELECT DestinationID, Code FROM mydata.dbo.ctryCode WHERE code Like LTRIM(RTRIM(@CountryCode)) +'%' Order by code Desc
OPEN Dest_cursor
FETCH NEXT FROM Dest_cursor INTO @TempCodeDestID, @CtryCode
WHILE @@FETCH_STATUS = 0
BEGIN
IF @MATCH <> 1
BEGIN
SET @MATCH = PATINDEX(@CtryCode + '%', @FormattedNbr);
IF @MATCH = 1
BEGIN
print @TempCodeDestID
SET @CodeDestID = @TempCodeDestID
END END
FETCH NEXT FROM Dest_cursor INTO @TempCodeDestID, @CtryCode
END
CLOSE Dest_cursor
DEALLOCATE Dest_cursor
IF @MATCH = 1
BEGIN
--Updating the maximum possible match
UPDATE mydata.dbo.CDR SET DestinationID = @CodeDestID WHERE CDRID = @CDRID
SET @CodeDestID = null;
SET @MATCH = 0;
END FETCH NEXT FROM CDR_cursor INTO @CDRID, @dialed_digits
Hi,is it possible to create a cursor from a dynamic string?Like:DECLARE @cursor nvarchar(1000)SET @cursor = N'SELECT product.product_idFROM product WHERE fund_amt > 0'DECLARE ic_uv_cursor CURSOR FOR @cursorinstead of using this--SELECT product.product_id--FROM product WHERE fund_amt > 0 -- AND mpc_product.status= 'aktiv'Havn't found anything in the net...Thanks,Peppi
Hello everybody!I have a small table "ABC" like this:id_position | value---------------------------1 | 112 | 223 | 33I try to use a dynamic cursor as below.When the statement "order by id_position" in declare part of the cursor_abcis omitted - cursor work as it should.But when the statement "order by id_position" is used, cursor behave asstatic one.What's the matter, does anybody know?Code:declare @id_position as int, @value as intDECLARE cursor_abc CURSORFORselect id_position, value from abcorder by id_positionset nocount onopen cursor_abcFETCH NEXT FROM cursor_abcINTO @id_position, @valueWHILE @@FETCH_STATUS = 0BEGINprint @id_positionprint @valueprint '----------------------------'update abc set value=666 --next reading should give value=666FETCH NEXT FROM cursor_abcINTO @id_position, @valueENDCLOSE cursor_abcDEALLOCATE cursor_abcGORegardsLucas
I've looked up Books Online on Dynamic Cursor/ Dynamic SQL Statement.
Using the examples given in Books Online returns compilation errors. See below.
Does anyone know how to use Dynamic Cursor/ Dynamic SQL Statement?
James
-- SQL ---------------
EXEC SQL BEGIN DECLARE SECTION; char szCommand[] = "SELECT au_fname FROM authors WHERE au_lname = ?"; char szLastName[] = "White"; char szFirstName[30]; EXEC SQL END DECLARE SECTION;
EXEC SQL DECLARE author_cursor CURSOR FOR select_statement;
EXEC SQL PREPARE select_statement FROM :szCommand;
EXEC SQL OPEN author_cursor USING :szLastName; EXEC SQL FETCH author_cursor INTO :szFirstName;
--Error-------------------- Server: Msg 170, Level 15, State 1, Line 23 Line 23: Incorrect syntax near ';'. Server: Msg 1038, Level 15, State 1, Line 24 Cannot use empty object or column names. Use a single space if necessary. Server: Msg 1038, Level 15, State 1, Line 25 Cannot use empty object or column names. Use a single space if necessary. Server: Msg 170, Level 15, State 1, Line 27 Line 27: Incorrect syntax near ';'. Server: Msg 170, Level 15, State 1, Line 30 Line 30: Incorrect syntax near 'select_statement'. Server: Msg 170, Level 15, State 1, Line 33 Line 33: Incorrect syntax near 'select_statement'. Server: Msg 102, Level 15, State 1, Line 35 Incorrect syntax near 'author_cursor'. Server: Msg 170, Level 15, State 1, Line 36 Line 36: Incorrect syntax near ':'.
i read in the SET ROWCOUNT documentation URL.... that 'The ROWCOUNT option does not affect dynamic cursors', it does affect my dynamic cursor created in a table function which looks like this :
CREATE FUNCTION MyTableFunction()Â RETURNS @MyTable TABLE (MYFIELD INTEGER) AS BEGIN Â DECLARE @xxx INTEGER Â DECLARE My_Cursor CURSOR DYNAMIC FOR Â [code]...
I would like the number of rows retruned by MyTableFunction limited to 2, but NOT the inside proc cursor's select !Set Rowcount 0 is forbidden in table function. I cannot use TOP in select * from MyTableFunction instead of setting ROWCOUNT to 2. I'm using SQL Server 2008 or 2012.
Hi, In a stored procedure (SP1) I call another stored procedure (SP2), passing along parameters. In SP2 I dynamically build cursor c1. I can execute SP2 without any problems but when I start SP1 I get the following message:
Msg 16916, Level 16, State 1, Procedure SP2, Line 114 A cursor with the name 'C1' does not exist.
Yes, the cursor is of type GLOBAL. I am sure I miss something here ... Any help is highly appreciated !
the cursor at the bottom  iterates only to print the number of rows.The problem is in the select. This takes 30 seconds to iterate through 1242 records.But if I add a TOP 1000000 or whatever number to the select, the same iteration takes less than a 1 second.I've tested each query without cursor, and  both have the same cost and performance. (Not exactly the same plan)Note that I got the same performance improvement declaring the cursor as STATIC.Why the top is affecting the cursor iteration so much?
DECLARE DBCur CURSOR FOR SELECT U_OB_DB FROM [@OB_TB04_COMPDATA]
OPEN DBCur FETCH NEXT FROM DBCur INTO @DBNAME
WHILE @@FETCH_STATUS = 0 BEGIN
SELECT @SQLCMD = 'SELECT T0.CARDCODE, T0.U_OB_TID AS TRANSID, T0.DOCNUM AS INV_NO, ' + + 'T0.DOCDATE AS INV_DATE, T0.DOCTOTAL AS INV_AMT, T0.U_OB_DONO AS DONO ' + + 'FROM ' + @DBNAME + '.dbo.OINV T0 WHERE T0.U_OB_TID IS NOT NULL' EXEC(@SQLCMD) PRINT @SQLCMD FETCH NEXT FROM DBCur INTO @DBNAME
END
CLOSE DBCur DEALLOCATE DBCur
Part 2
SELECT T4.U_OB_PCOMP AS PARENTCOMP, T0.CARDCODE, T0.CARDNAME, ISNULL(T0.U_OB_TID,'') AS TRANSID, T0.DOCNUM AS SONO, T0.DOCDATE AS SODATE, SUM(T1.QUANTITY) AS SOQTY, T0.DOCTOTAL - T0.TOTALEXPNS AS SO_AMT, T3.DOCNUM AS DONO, T3.DOCDATE AS DO_DATE, SUM(T2.QUANTITY) AS DOQTY, T3.DOCTOTAL - T3.TOTALEXPNS AS DO_AMT INTO #MAIN FROM ORDR T0 JOIN RDR1 T1 ON T0.DOCENTRY = T1.DOCENTRY LEFT JOIN DLN1 T2 ON T1.DOCENTRY = T2.BASEENTRY AND T1.LINENUM = T2.BASELINE AND T2.BASETYPE = T0.OBJTYPE LEFT JOIN ODLN T3 ON T2.DOCENTRY = T3.DOCENTRY LEFT JOIN OCRD T4 ON T0.CARDCODE = T4.CARDCODE WHERE ISNULL(T0.U_OB_TID,0) <> 0 GROUP BY T4.U_OB_PCOMP, T0.CARDCODE,T0.CARDNAME, T0.U_OB_TID, T0.DOCNUM, T0.DOCDATE, T3.DOCNUM, T3.DOCDATE, T0.DOCTOTAL, T3.DOCTOTAL, T3.TOTALEXPNS, T0.TOTALEXPNS
my question is, how to join the part 1 n part 2? is there posibility?
I am stuck in a bit of a conundrum for quite a while now, and I hope someone here will help me figure this one out.
So, first things first: let me explain what I need to do. I am designing a web application that will allow users to consult info available in a SQL2000 database. The user will enter the search criterea, and hopefully the web page will show matching results.
The problem is the results shown aren't available per se in the DB, I need to process the data a bit. I decided to do so on the SQL Server side, though the use of cursors. So, when a user defines his search criteria, I run a stored procedure that begins by building a dynamic sql query and creating a cursor for it. I used a global cursor in order to do so. It looked something like this:
SET @sqlQuery = ... (build the dinamic sql query)
SET @cursorQuery = 'DECLARE myCursor CURSOR GLOBAL FAST_FORWARD FOR ' + @sqlQuery
EXEC @cursorQuery
OPEN myCursor
FETCH NEXT FROM myCursor INTO ...
CLOSE myCursor
DEALLOCATE myCursor
This works fine, if there's only one instance of the stored procedure running at a time. Should another user connect to the site and run a search while someone's at it, it'll fail due to the atempt to create a cursor with the same name.
My first thought was to make the cursor name unique, which led me to:
...
SET @cursorName = 'myCursor' + @uniqueUserID
SET @cursorQuery = 'DECLARE '+ @cursorName + 'CURSOR FAST_FORWARD FOR ' + @sqlQuery
EXEC @cursorQuery
...
The problem with this is that I can't do a FETCH NEXT FROM @cursorName since @cursorName is a char variable holding the cursor name, and not a cursor variable. So to enforce this unique name method the only option I have is to keep creating dynamic sql queries and exucting them. And this makes the sp a bitch to develop and maintain, and I'm guessing it doesn't make it very performant.
So I moved on to my second idea: local cursor variables. The problem with this is that if I create a local cursor variable by executing a dynamic query, I can't extract it from the EXEC (or sp_executesql) context, as it offers no output variable.
I guess my concrete questions are:
Is it possible to execute a dynamic sql query and extract a (cursor) variable from it?Is it possible to populate a local cursor variable with a global cursor, by providing the global cursor's name?Can I create a local cursor variable for a dynamic sql query? How?
Anybody sees another way arround this?Thanks in advance,
I need to find all uses of special characters in a database. I used the following code to do this:
USE dbName GO IF OBJECT_ID('tempdb.dbo.#Results') IS NOT NULL DROP TABLE #Results GO
[code]...
This will check all tables in the database, but if you want to check specific tables you can uncomment the line in the where clause and specify tables to be checked. The query will return any text fields that have any characters other than letters, numbers or spaces.
This code works fine for me because all the tables in my database have single column primary keys. However I know how much Jeff Moden hates cursors or RBAR queries, so my question is could this have been done by any method other than using a cursor?
I'm new to cursors, and I'm not sure what's wrong with this code, it run for ever and when I stop it I get cursor open errors
declare Q cursor for select systudentid from satrans
declare @id int
open Q fetch next from Q into @id while @@fetch_status = 0 begin
declare c cursor for
Select b.ssn, SaTrans.SyStudentID, satrans.date, satrans.type, SaTrans.SyCampusID, Amount = Case SaTrans.Type When 'P' Then SaTrans.Amount * -1 When 'C' Then SaTrans.Amount * -1 Else SaTrans.Amount END
From SaTrans , systudent b where satrans.systudentid = b.systudentid
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server with aparticular query. It would take approximately 22 seconds to return 100rows, thats about 0.22 seconds per row. Note: I ran the query in singleuser mode. So I tested the query on the Development server by taking abackup (.dmp) of the database and moving it onto the dev server. I ranthe same query and found that it ran in less than a second.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue is relatedto some external hardware issue like: disk space, memory etc. Or couldit be OS software related issues, like service packs, SQL Serverconfiguations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating system related issue.Any Ideas would help me greatly!Thanks,Brian T*** Sent via Developersdex http://www.developersdex.com ***
I having a difficult time here trying to figure out what to do here.I need a way to scroll through a recordset and display the resultswith both forward and backward movement on a web page(PHP usingADO/COM)..I know that if I use a client side cursor all the records get shovedto the client everytime that stored procedure is executed..if thisdatabase grows big wont that be an issue?..I know that I can set up a server side cursor that will only send therecord I need to the front end but..Ive been reading around and a lot of people have been saying never touse a server side cursor because of peformance issues.So i guess im weighing network performance needs with the client sidecursor vs server performance with the server side cursor..I am reallyconfused..which one should I use?-Jim
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server witha particular query. It would take approximately 22 seconds to return100 rows, thats about 0.22 seconds per row. Note: I ran the query insingle user mode. So I tested the query on the Development server bytaking a backup (.dmp) of the database and moving it onto the devserver. I ran the same query and found that it ran in less than asecond.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue isrelated to some external hardware issue like: disk space, memory etc.Or could it be OS software related issues, like service packs, SQLServer configuations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating systemrelated issue.Any Ideas would help me greatly!Thanks,Brian T
Hi, I have just upgrade my sql 6.5 to 7.0 version. This sql box (compaq proliant 5500) has 1 gig ram and 4 pentium pro processors and smart array controller. There are about 200 users hit on that server constantly. I configured this server according compaq white paper and Microsoft recommendation; however, I am still suffering huge performance hit. Then I setup performance monitor to see what is happening. What I see is all of 4 processors are at 70% processor time constantly. What I heard is sql 7.0 runs much better on pentium III processors. Is that true? Or you have any recommendations??
