So i tweaked a stored procedure that did a 1 hour update for a specific countryId.
If that procedure was called at the same time with two different countryId than one update took place and afterwards the other.
Since all the rows are distinct i switched to an batch update only updating 10000 rows at a time ( and not all of the 2 million).
The general locking looked better afterwards but now i receive strange deadlocks.
My theory:
TX1 Updates a row on Page1 (P1) with rowlock. TX2 also does this on P1. Now TX1 deceides to escalate to PAGELOCK. TX1 waits for TX2 to be done with the row so it can lock the page. TX2 waits for TX1 to leave the page since TX2 may also want to pagelock.
Everybody waits for each other so we have a deadlock. Is that feasible ? OR is there another common problem when doing batch updates on the same table with distinct rows ( that can be on a same datapage ofc).
I want to update tableToUpdate in batches of 5000 per batch and set the lastenecryptionDT to null based on the the join to the tableValues using the column ENCRYPTIONID, and also output updated rows into another table. Incase I would need to do a rollback.
what are the best ways to action on the Deadlock issues. I am aware how a deadlock is occurred and we can get the queries causing by the Trace, and Profiler. What will en best steps to Investigate from DBA end later collecting the stats.What steps will ensure to get these deadlocks addressed.
We know we can use the event lock_deadlock and xml_deadlock_report to capture the deadlock info, however I also want to capture the execution plans for all of the SPIDs in the deadlock graph, how to output the execution plans to the extended events trace results either ? such as if there is an action for execution plan or workaround for it ?If there is no built in action for execution plan , may I know if we can add the customized info to the extended events results file also ? Such as when the deadlock related event happens , then we can run a query to get some info ,then added the info along with other info such as sql_text, dbname etc  to the events trace results file either ? The reason is if we also know the execution plans when the deadlock happens, it is useful to turning the query based on the execution plans to reduce deadlock happening .
I need to update the ilocationid from Table 1 to all Table 2 records related to Table 1but there is no direct relation from Table 1 to Table 2. I needed Table 3 to make the connection from Table 1 to 2.
Is there a way to send out an email woth deadlock information (victim query, winner query, process id's and resources on which the deadlock occurred) as soon as a deadlock occurs in a database or at instance level?I currently has trace flag 1222 turned on. And also created an alert that send me an email whenever a deadlock occurs. but it just says that a deadlock occurred and I log into sql server error log and review the information.
visual studio.net seems to default to single batch mode when runningsql scripts. does anyone know how to change this behavior? typicalbatches will include object existence, drop, and create batches priorto processing. i have attempted removing the graphical plan, usingbatch separator 'go', and the vba trick using ';' to no avail.tia
I am using SQL Server Express and Visual Studio 2005. I am new to batches and am trying to understand how they work. I am trying to write a query that creates an assembly and the functions that are contained in it. Here is my query:
USE ProductsDRM GO
IF NOT EXISTS (SELECT 'True' FROM sys.assemblies WHERE name = 'ComputedColumnFunctions') BEGIN CREATE ASSEMBLY ComputedColumnFunctions FROM 'C:WebsitesAssemblyTestStoredFunctionsStoredFunctionsinStoredFunctions.dll' GO
CREATE FUNCTION fImageFileName ( @ProductID int, @ImageSizeCode nvarchar(4000) ) RETURNS nvarchar(4000) AS EXTERNAL NAME [ComputedColumnFunctions].[StoredFunctions.UserDefinedFunctions].ImageFileName GO
CREATE FUNCTION fTestInt ( @ProductID int ) RETURNS int AS EXTERNAL NAME [ComputedColumnFunctions].[StoredFunctions.UserDefinedFunctions].TestInt GO
CREATE FUNCTION fTestInt2 ( @TestInt int ) RETURNS int AS EXTERNAL NAME [ComputedColumnFunctions].[StoredFunctions.UserDefinedFunctions].TestInt2 END ELSE BEGIN PRINT 'The assembly named "ComputedColumnFunctions" already exists. No new assembly was created.' END
GO
I read in a book about SQL Server 2005 about including a test for whether the object (such as assembly in this case) exists before trying to create it. If I only include the CREATE ASSEMBLY statement and the FROM line below it and delete the next GO down through the last CREATE FUNCTION (just before the END ELSE), it works fine. If I leave it as is, I get a runtime error on the GO line just after the CREATE ASSEMBLY statement. What am I doing wrong?
I have an application that processes a large number of input files in a CSV format and then posts the data to a table on SQL Server Express.
The data table can end up very large and I have no requirements to store all the data locally. I have included the table in my DataSet using visual studio express so I have access to the schema, but will not run Fill() on it.
Ideally I would like to process a CSV file at a time. I can add records to my local (empty) data table and when I am happy, I can call tableAdapter.Update() or dataSet.DataTable.AcceptChanges() to generate lots of SQL 'INSERT' commands to update the physical database at the server end.
I would then like to empty my local data table (so it doesn't get too big) and repeat the same process over again for each CSV file.
How can I empty my local table without causing it to generate a load of SQL 'DELETE' commands? I want to empty the table and fool ADO.NET into thinking that everything is synchronised, as if it has just done an update but actually hasn't.
Hello SQL Team! I'm stuck at this problem for days and need help. The problem is with the GO keyword. I know the GO causes the batch to get executed and all local variables are lost. But I can't seem to find a work around. I would like each stored procedure to get executed in different batches.
create table sql_cmd(cmd nvarchar(255)) insert into sql_cmd(cmd) values('exec user_sp param1,''param2'') insert into sql_cmd(cmd) values('exec user_sp2 param1,''param2'')
declare @sql nvarchar(255) declare c_sql cursor --small table peformance not a problem. Also open to other suggestions for select cmd from sqlcmd open c_sql fetch next from c_sql into @sql while @@fetch_status = 0 begin print @sql exec sp_executesql @sql GO fetch next from c_sql into @sql end
Recently I was stumped on a problem where I was granting permissions to a user, from within a script that was creating a stored procedure. Then I would check the permissions on the procedure, but the permissions were empty. It turned out that I was missing a "go" statement to seperate the create procedure statement from the grant statement. So that got me to thinking about what other kids of statements must be seperated into seperate batches ? I would thik that anything that is being created must be seperated from any statements that grant or alter permissions, because the items would need to exist first.
I have a query batch "update" script that upgrades my users database from,say version 0 to version 1, or from version 1 to version 2. I would like toknow how I can wrap the entire script in a transaction, so that either thewhole thing succeeds or none of it does.For example:BEGIN TRANSACTION.......... Alter some tables.....GO.......... Alter a stored procedure.....GO.......... Create a new stored procedure.....GOCOMMIT TRANSACTIONorROLLBACK TRANSACTIONGO(how do I get to the "ROLLBACK TRANSACTION" if an error occurs in the updatescript?)
Hi, I would like to delete a data from a 750million row table in chunks of 10000,without blocking the users.As ours is a 24/7 shop I donot want to block the users for a long time. Answer for this is highly appreciated. Thanks Samna
I need to group up the records randomly into ‘n’ number of batches. That can be done by NTILE, but I want group up similar records in single group.
Say for example, following is the list of records I have in my table which I want to group into 5 batches
A123 A124 A124 A123 A127
After Ntile I will get the below,
Desired output is, Need output like Ntile but all same id should reside in single batch
Even if I n=5, maximum possibility of batches are 3 only.
In another forum post, a poster was deleting large numbers of rows from a table in batches of 50,000.
In the bad old days ('80s - '90s), I used to have to delete rows in batches of 500, then 1000, then 5000, due to the size of the transaction rollback segments (yes - Oracle).
I always found that increasing the number of deleted rows in a single statement/transaction improved overall process speed - up to some magic point, at which some overhead in the system began slowing the deletes down, so that deleting a single batch of 10,000 rows took more than twice as much time as deleting two batches of 5,000 rows each.
good rule-of-thumb numbers (or even better, some actual statistics and/or explanations) as to how many records should be deleted in a single transaction/statement for optimum speed? 50,000 - 100,000 - 1,000,000 or unlimited? Are there significant differences between 2008, 2012, 2014?
We are using the Transfer SQL Server Objects Task to transfer a large table. The trans log is filling up for this table. Is there a method to split the Data Transfer Task into smaller batches? (Smaller tables are transferring without issue.)
We have a SQLServer 2005 Enterprise merge replication publication with SQL Mobile 3.0 subscribers (Windows Mobile 5.0 and 6.0). We do not use pre-computed partitions due to trigger performance issues with an SSIS/ETL application that supplies data to the merge database. We do use the "Optimize" (=true) option, though we have tried this both ways with no significant differences. We use filters and joins for each worker ID (as HOST_ID) from the subscriptions.
The sync times become increasingly worse after we run the snapshot and bring the publication online. I have tried rerunning the snapshots, this helps little, as it often behaves like the subscription was set to reinitialize and forces a big sync (reload of all data) to the subscriber. We have tried much of the obvious (e.g., flattening filters and joins, adding indexes, etc.).
When users are synchronizing, we watch replication monitor and notice that a lot of time is spent processing "enumerating inserts and updates for article [any article]", especially processing the many generations and batches. This is true for any follow-up syncs after the 1st big sync (initializing the subscription).
I read several posts regarding the batches and generations of changes, and decided to try increasing the €œDownloadGenerationsPerBatch€?. I tried adding this parameter to the snapshot agent job, and the job fails each time with a vague message, even with the default value of 100. How do you change this parameter for SQLServer 2005 Enterprise?
I am very new to SQL Server 2005. I have created a package to load data from a flat delimited file to a database table. The initial load has worked. However, in the future, I will have flat files used to update the table. Some of the records will need to be inserted and some will need to update existing rows. I am trying to do this from SSIS. However, I am very lost as to how to do this.
In a high traffic environment, deadlocks eventually occur as number of data processes increase. How can deadlocks be avoided, minimized and resolved. Please kindly provide scenario examples and samples of T-SQL code. Thanks much.
Iam trying to bcp a table(residing on my prod server to my local machine from command prompt) .Actually the table iam trying to bcp has heavy updates and selects, from users (70 users). The users complain that system becomes slow.Is it got anything to do with my trying to bcp the mentioned table(table has 170,000 records).Also whenever i try to bcp this table, only after being chosen as the deadlock victim by Sql server,for 3 or 4 times that iam able to bcp the table.
Any help regarding this will be very much appreciated TIA kinnu
I am unable to control the granularity of locks in our queries. We are running queries through MTS and are getting deadlocks.
The batch includes two inserts and one select query - all are hitting on only one table. This table has a unique clustered and a unique nonclustered index as well as a primary key.
Within the batch, I have given a table hint to set transaction isolation level to READCOMMITTED, ROWLOCK for the insert statements, like this
INSERT INTO ib_price with (READCOMMITTED,ROWLOCK)........
and the same for the Select statement.
SELECT retail_price, price_status_id FROM ib_price with (READCOMMITTED,ROWLOCK)
When I run sp_lock on the spid, I get output indicating that SS7 is placing a IX lock on the table. I'm pretty sure this is a big contributor to the deadlock.
I get the deadlock when I try to run more than one client with similar insert parameters.
How can I control the granularity to just rowlocks?
I am getting deadlock running a stored procedure from two machines. Looking at the error log (generated using trace flag 1204 and 3605), it seems the deadlock is on a key. But what I fail to understand is how come sql server granted exclusive lock on the key to both connections. The grant list shows that lock with Mode X is granted to both connection.
Can anyone help me resolve deadlock with following text
Parallel Query worker thread Involved in deadlock.
I am particularly interested in resolving details of above mentioned line,as I started getting dead lock more frequently now and when I look into query involved blocking and victim I see nothing that can cause deadlock they are update insert and select statement which were fine for long and all of sudden started giving problem.
Thanks in advance, for any knowledge share my mail id scraval@hotmail.com
Hi, When many users run some stored procedures I 've got some deadlocks. How to avoid that? We run large stored procedures code which are using sometime the same table. What is the best way for using the transaction isolation level, fillfactor indexes, procedure cache configuration ...etc to avoid that.
In addition, I am using MTS and sometimes the Tempdb is also locked, is it a Microsoft bug (again) ?
We had a dead lock every night 9:00pm. I found out Server/Current Activity --Object Locks : The error log showing error 17824, severity:10, state 0 DNCC TRACEON 208, SPID 28 DBCCTRACEOFF 208, SPID 28 In current activity --object locks and reapetedly showing "tempdb.dbo.sysobjects/sysindexes/syscolumns" 28:sa.master.dbo /INSERT /SQL_servername (MS SQLEW)
Sorry for bombading the forum with all these questions, but i am relatively new to sql 2000.
I am getting dead lock on the following procedure.
important background information 1. this is a multi user web-based call centre application 2. this procedure loads up a new contact based on priority
I see no reason how a dead lock could occur. does any one have any idea. could it be something else that is locking up resource used by this procedure?
CREATE PROCEDURE topcat.getNewContactInfo ( @contact_id int ) AS BEGIN begin transaction
declare @id int
set @id = (SELECT TOP 1 _id FROM class_contact WHERE (status IS NULL OR status='New Contact' OR status = 'No Connect' OR status='callback') AND (checked_in IS NULL OR checked_in <> 1) AND (callback_date >= (getdate() + 1) OR callback_date IS NULL ) ORDER BY priority DESC)
UPDATE class_contact SET checked_in = 1 WHERE _id = @id SELECT TOP 1 * FROM class_contact WHERE _id = @id
commit END GO
wat i dont' get is that, this procedure only has one update statement, this is the only statement that could possibly hold a lock on another resource (i think) , i can't see how a dead lock can happen in this case since this procedure doesn't hold up 2 resources at a time.
