Transaction Lockout Of Reads

Aug 28, 2006

Hi,

I have been seeing a basic scenario of a write transaction appearing to unexpectedly lock-out reading.

The database has isolation set to "READ COMMITTED".

The scenario is:

1.) Start a transaction (for doing a write)

2.) Do a read before the transaction (for doing the write) is committed (e.g. sqlCommand2.ExecuteReader()).

--> the code will appear to lock-up (then time out).

I see the same behavior if I step through the "write" code with the debugger (to a point after the transaction is started, but before it is committed), and run a "SELECT * FROM" type query from Microsoft SqlServer Management Studio.

Following is the code sample demonstates the issue.

Thoughts on how to resolve the issue (to let me do "read committed" reading of the database table)?

Thanks!

Andy







Module Transaction

Sub Main()

Dim exception1 As Exception

Try

' Create/Open Database Connection

Dim sqlConnection1 As New System.Data.SqlClient.SqlConnection("Server=GRB-AB;Database=Transaction;Trusted_Connection=True;")

sqlConnection1.Open()

' Start transaction

Dim sqlTransaction1 As System.Data.SqlClient.SqlTransaction = sqlConnection1.BeginTransaction()

' Set Parent record

Dim sqlCommand1 As New System.Data.SqlClient.SqlCommand("INSERT INTO Parent (Name) VALUES ('ParentValue');", sqlConnection1)

sqlCommand1.Transaction = sqlTransaction1

sqlCommand1.ExecuteNonQuery()

' Get Id from parent record (note: this code assumes the table was empty when this program starts)

sqlCommand1 = New System.Data.SqlClient.SqlCommand("SELECT Id FROM Parent;", sqlConnection1)

sqlCommand1.Transaction = sqlTransaction1

Dim parentId As Integer = CType(sqlCommand1.ExecuteScalar(), Integer)



'

' Do reading test to test concurrently reading table being written to

'

' Create/Open Database Connection for reading test

Dim sqlConnection2 As New System.Data.SqlClient.SqlConnection("Server=GRB-AB;Database=Transaction;Trusted_Connection=True;")

sqlConnection2.Open()

Dim sqlCommand2 As New System.Data.SqlClient.SqlCommand("SELECT Id FROM Parent;", sqlConnection2)

sqlCommand2.ExecuteReader()

Dim i As Integer

While (sqlCommand2.ExecuteReader.Read = True) ' <===== LOCKS UP HERE **************

i = i + 1

End While

'

' End reading test

'



' Set child record

sqlCommand1 = New System.Data.SqlClient.SqlCommand( _

"INSERT INTO Child (Name, ParentId) VALUES ('ChildValue', " & parentId.ToString & ");", sqlConnection1)

sqlCommand1.Transaction = sqlTransaction1

sqlCommand1.ExecuteScalar()

' Either 1.) commit transaction OR 2.) rollback transaction

Dim test As Boolean = False

If test = False Then

sqlTransaction1.Commit()

Else

sqlTransaction1.Rollback()

End If

sqlConnection1.Close()

sqlConnection2.Close()

Catch ex As Exception

exception1 = ex

End Try

End Sub

End Module

View 1 Replies


ADVERTISEMENT

Connection Lockout

Oct 24, 1999

I have a custom application running against sql7 that has twice "locked up" sql7. The locked up symptom is that sql 7 will not allow any connections,
even from enterprise manager (server xxxxx is not responding........). The application returns an error that says the
"xxxxx" database is not available, using master instead. A look at the NT event log and the sql7 log provide no help. The OS is running fine and
existing connections (by the application) are still allowing database writes. How do trap what is causing sql7 to stop responding to connection
requests. I am presently starting and stopping the mssql service to get things running, but I really need a root cause. Any troubleshooting tips for
this would be greatly appreciated. Thanks in advance!

View 1 Replies View Related

User Lockout

Feb 11, 2008

Can anyone tell me how a user gets lockedout in sql 2005. ?

View 4 Replies View Related

Account Lockout Problem With Sp_send_dbmail

Sep 1, 2006

I am running this code in a job:

EXEC msdb.[dbo].sp_send_dbmail
@profile_name = 'Blah Blah',
@recipients = 'blah@blah.com',
@subject = 'Server Report 1',
@body = '',
@execute_query_database = 'DBInfo',
@query = 'EXEC dbo.usp_SvrRpt1;',
@query_result_header = 0,
@query_result_width = 300,
--@attach_query_result_as_file = 1,
@query_result_separator = '';
GO

Because I am creating a total of 6 server reports, I alter the subject and query like so:

@subject = 'Server Report X' --where X is replaced with values 1 to 6
@query = 'EXEC dbo.usp_SvrRptX' --where X is replaced with values 1 to 6

I can run 4 reports without any problems. If I run more than 4 reports in the same batch, my network account under Windows 2000 Activity Directory is locked out as if I had erroneously mistyped my password the number of time to meet the lockout requirement - in this case, the number is 3 login tries.

Is this a known problem with Database Mail? If so, is there a fix or workaround?

Thanks,

Neal

View 8 Replies View Related

Transact SQL :: Lockout Time In Milliseconds

Dec 1, 2015

why does select @@lock_timeout return -1. Shouldn't this return lock timeout in milliseconds?

View 2 Replies View Related

SQL Security :: Authentication Lockout Option

May 24, 2015

Does SQL Server have any place to configure an account Lockout Threshold  (SQL-authentication), also is there a default value (how many times failed logging would be initiated before the user lockout?)

View 7 Replies View Related

Error 8525: Distributed Transaction Completed. Either Enlist This Session In A New Transaction Or The NULL Transaction.

May 31, 2008

Hi All

I'm getting this when executing the code below. Going from W2K/SQL2k SP4 to XP/SQL2k SP4 over a dial-up link.

If I take away the begin tran and commit it works, but of course, if one statement fails I want a rollback. I'm executing this from a Delphi app, but I get the same from Qry Analyser.

I've tried both with and without the Set XACT . . ., and also tried with Set Implicit_Transactions off.

set XACT_ABORT ON
Begin distributed Tran
update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.TRANSACTIONMAIN
set REPFLAG = 0 where REPFLAG = 1
update TSADMIN.TRANSACTIONMAIN
set REPFLAG = 0 where REPFLAG = 1 and DONE = 1
update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.WBENTRY
set REPFLAG = 0 where REPFLAG = 1
update TSADMIN.WBENTRY
set REPFLAG = 0 where REPFLAG = 1
update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.FIXED
set REPFLAG = 0 where REPFLAG = 1
update TSADMIN.FIXED
set REPFLAG = 0 where REPFLAG = 1
update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.ALTCHARGE
set REPFLAG = 0 where REPFLAG = 1
update TSADMIN.ALTCHARGE
set REPFLAG = 0 where REPFLAG = 1
update OPENDATASOURCE('SQLOLEDB','Data Source=10.10.10.171;User ID=*****;Password=****').TRANSFERSTN.TSADMIN.TSAUDIT
set REPFLAG = 0 where REPFLAG = 1
update TSADMIN.TSAUDIT
set REPFLAG = 0 where REPFLAG = 1
COMMIT TRAN


It's got me stumped, so any ideas gratefully received.Thx

View 1 Replies View Related

Many Reads

Mar 25, 2008

Hi!
I was assigned to solve performance problems for an application. I fired up Sql Server profiler and started a trace. Downloaded Sql Server Trace Analyzer. It's a trial version so it's very limited. What I found is that one stored procedure generates almost 400 000 reads everytime it's used and it's used everytime the user wants to see his orders. I've tried to translate the t-sql to english from swedish, it looks something like this:


select top 100
o.orderid,
o.name,
o.latestdeldate,
os.name as OrderStatus,
os.orderstatusID,
p.placeID,
p.name as place,
p.address,
p.city,
a.name as worktype,
noOfActions=(select count(*) from actions a where a.order_orderid=o.orderid),
noOfServiceObjects = (select count(*) from Serviceobject s, Actions a where s.Place_PlaceID = o.Place_PlaceID and a.order_orderid = o.orderid and a.Serviceobject_serviceobjectid = s.serviceobjectid),
...
...
...


It has 8 select count(*) in the select statement then in the where statement it has 2 more select count(*).

I know it's very difficult for you to come up with a solution but do you know a better way than to use select count(*) everywhere? The count is used for to show different status flags on the website.

/Magnus

Jesus saves. But Gretzky slaps in the rebound.

View 19 Replies View Related

SSIS, Distributed Transaction Completed. Either Enlist This Session In A New Transaction Or The NULL Transaction.

Feb 22, 2007

I have a design a SSIS Package for ETL Process. In my package i have to read the data from the tables and then insert into the another table of same structure.

for reading the data i have write the Dynamic TSQL based on some condition and based on that it is using 25 different function to populate the data into different 25 column. Tsql returning correct data and is working fine in Enterprise manager. But in my SSIS package it show me time out ERROR.

I have increase and decrease the time to catch the error but it is still there i have tried to set 0 for commandout Properties.

if i'm using the 0 for commandtime out then i'm getting the Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.

and

Failed to open a fastload rowset for "[dbo].[P@@#$%$%%%]". Check that the object exists in the database.

Please help me it's very urgent.

View 3 Replies View Related

Dirty Reads

Aug 1, 2001

If I'm doing a dirty reads and a someone updates a record when I'm trying to read it is it possible to read both the old and new records thereby retrieving two records?

View 2 Replies View Related

Reads / Writes Per Second.

Oct 30, 2006

How can You find the reads and writes per second of your hard drives in sql. I am reading my SQL book and it says that your average disk should have 125 or less i/o's. And it gave the forumal but as mentioned I don't know how to find the reads and writes.

View 4 Replies View Related

Reads, Clustering, Etc

May 1, 2008

server: QAT on clustering server ----> 23 seconds
----------------------------------------------------
SS 2000 developer edition SP4
win NT 5.2 (3790) SP4
MeM 7935 MB
processors 4
root directory C:program files...
use a fixed memeroy size 640 MB

reserve physical memory for sql server
minimum query memory 1024 kb

use all available processors
minimum query plan threshold for considering 5

PROFILER READS = 5234




server: MILLER ----> 3 seconds
----------------------------------------------------
SS 2000 developer edition no service pack
win NT 5.2 (3790) SP4
MeM 2047 MB
processors 4
root directory f:MSSQL$INAQAT

dynamically configure sql server memory

use all available processors
minimum query plan threshold for considering 5
PROFILER READS = 598





----------------------------------------------------
Making story short. I got an application that hits only 1 database called RECORDS. I'm getting different duration when running an application. 23 and 3 seconds.
Same database, same objects and same application.
SERVER QAT is our staging server, means lots of databases
SERVER MILLER is just a server i just assembled, means just one database (RECORDS).

Not sure if it's because it's a clustering server that is causing the issue nor the reads. If its the reads, what is causing it? Do you think is the how the memory is configured?. Will the experts pls stand up?

View 20 Replies View Related

More Reads Then Expected

Jul 18, 2006

So I€™m at a dead-end looking for the reason behind the following behavior. Just to make sure no one misses it, the 'behavior' is the difference in the number of reads between using sp_executesql and not.

The following statements are executed against a SQL 2000 database that contains >1,000,000 records in the act_item table. They are run using Query Analyzer and the Duration and Reads come from SQL Profiler

SQL 1:
exec sp_executesql N'update act_item set Priority = @Priority where activity_code = @activity_code', N'@activity_code nvarchar(40),@Priority int', @activity_code = N'46DF335F-68F7-493F-B55E-5F9BC6CEBC69', @Priority = 0

Reads: ~22000
Duraction: 250-350 ms

SQL 2:
DECLARE @Priority int
DECLARE @Activity_Code char(36)

SET @Priority = 0
SET @Activity_Code = '46DF335F-68F7-493F-B55E-5F9BC6CEBC69'
update act_item set Priority = @Priority where activity_code = @activity_code

Reads: ~160
Duration: 0 ms

Random information:

Activity_code is an indexed field on the table, although it is not the primary key. There are a total of four indexes on the table, none of which include the priority as one of the fields.
There are two triggers on the table, neither of which is executed for this SQL statement (there is an IF UPDATE(fieldname) surrounding the code in the trigger)
There are no foreign relationships
I checked (using perfmon) to see if a compilation/recompilation was happening. No it's not.
Any suggestions as to avenues that could be examined would be appreciated.

TIA

View 3 Replies View Related

Distributed Transaction Completed. Either Enlist This Session In A New Transaction Or The NULL Transaction.

Feb 6, 2007

I am getting this error  :Distributed transaction completed. Either enlist this session in a new
transaction or the NULL transaction. Description:
An unhandled exception occurred during the execution of the current web
request. Please review the stack trace for more information about the error and
where it originated in the code. Exception Details:
System.Data.OleDb.OleDbException: Distributed transaction completed. Either
enlist this session in a new transaction or the NULL transaction.have anybody idea?!

View 1 Replies View Related

Distributed Transaction Completed. Either Enlist This Session In A New Transaction Or The NULL Transaction.

Dec 22, 2006

i have a sequence container in my my sequence container i have a script task for drop the existing tables. This seq. container connected to another seq. container. all these are in for each loop container when i run the package it's work fine for 1st looop but it gives me error for second execution.

Message is like this:

Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.

View 8 Replies View Related

Distributed Transaction Completed. Either Enlist This Session In A New Transaction Or The NULL Transaction. (HELP)

Jan 8, 2008

Hi,

i am getting this error "Distributed transaction completed. Either enlist this session in a new transaction or the NULL transaction.".

my transations have been done using LINKED SERVER. when i manually call the store procedure from Server 1 it works but when i call it through Service broker it dosen't work and gives me this error.



Thanks in advance.


View 2 Replies View Related

Sqldatareader Reads From Second Row Skip The First Row.

Jun 20, 2007

Hello,
im using sqldatareader to read my data and whenever time i loop through the reader it starts from second row why is that?
here is my code:while (reader.Read()){hinfo.Name = reader["_name"].ToString();hi.Add(hinfo);}
i look at the database and i have two rows but its reading only the second row, skiping the first row 
 

View 2 Replies View Related

Log Reads In SQL Server 2005

May 31, 2006

I have a set of triggers that log the history of changes to a table - i.e. I record inserts, updates, deletes (pretty standard audit stuff I suppose). I want to also log reads on that data. If I were using sprocs for reading data, this would be relatively painless, but I am using an O/R mapper to handle my data access, which writes dynamic sql at runtime (and I don't want to use sprocs with it) and then sends it down to the DB. Is there a way I can intercept reads and log them to the same table I am logging other actions? I know very little about the new capabilities of SQL Server 2005, but I would think I could somehow, maybe via the new CLR capabilities or similar, get access to these types of events within the database? Anyone? I know I could always do this higher up in the application layers, but I would like to keep all of this at the database level if possible....Thanks,

View 1 Replies View Related

High Page Reads

Jan 17, 2002

SQL 6.5 - 5.5 Gig
NT

Hello,

Throughout the day our Document Management application generates high busts of physical page reads when users query the database.

What SQL configuration parameter(s) should I check/modify to insure that the database is performing at it's optimun during these bursts?

Thank You in advance.

View 1 Replies View Related

COUNT Of READS And WRITES On A 6.5 Db.

Jul 21, 2000

Is there a way to get a total count of all SELECT, UPDATE, DELETE and INSERT statements to a SQL Server 6.5 database during a 12 hour period? I'm thinking maybe someone knows of a software that reads the log or monitors the server... I've been looking at the performance monitor and, although it has good information, it doesn't capture DML's.

FYI - it's for capacity planning.

TIA,
Mike

View 1 Replies View Related

Reducing Reads Question

Aug 24, 2007

I'm trying to insert all the rows from a table to a new table.
(insert A select * from AA)
The reads on Profiler shows ar really high value (10253548).

First I created a unique clustered index and the reads shows (3258445), then I created a non clustered index expecting to have lower reads. Instead the reads shows (10253548).

I read creating indexes helps reduce reads. But it's not happening.
Any ideas what is going on?

=============================
http://www.sqlserverstudy.com

View 6 Replies View Related

Track Reads And Writes

Mar 5, 2008

GUys,

Is there any way track tables which have most no of reads and writes from a database of 400 tables.

Thanks

View 9 Replies View Related

Number Of Reads In Profiler

Jul 27, 2007

Hi,

Can any of can explain, what the "Reads" column in Profiler exactly mean ? I'm not comfortable with the explanation given in BOL.


"The number of read operations on the logical disk that are performed by the server on behalf of the event. These read operations include all reads from tables and buffers during the statement's execution"

For the same procedure with same parameters, if the server is not loaded much, the Reads are in a few hundreds, but when there are more than 1000 concurrent users, why it is going to millions ? What other parameters affecting this reads ? And how can I reduce it ?

Environment: SQL Server 2005 64-bit Enterprise Edition on Windows Server 2003 R2 Server x64 Enterprise Edition SP2


Thanks in Advance.

Regards

Babu

View 4 Replies View Related

SQL CLR Stored Proc Reads

Sep 19, 2006

I have written a same stored proc in TSQL and SQL CLR which basically takes an input xml and returns xml document. In SQL Profiler, I am getting reads value about five times more for the CLR. Does anyone has any idea why the CLR is doing more reads than TSQL? Thanks in advance.

View 5 Replies View Related

Query Logical, Scan Reads?

Dec 22, 2000

Hi Everybody,

One of my friend asked me "How do we reduce the query logical, scan reads
in SQL Server?".

I really don't know, how to answer him.

Can anybody explain me regarding this.

thanks,
Srini

View 2 Replies View Related

SQL 2012 :: Deadlocking Under Repeatable Reads

May 5, 2015

Just migrated application from Oracle to SQL and we are seeing alot of deadlocking and blocking. I did notice that app seems to be passing isolation level of repeatable read. Attached is a .doc of one of the deadlocks, is there a way to avoid these in the repeatable read isolation level? This example is a select with two tables, using NCI's that cover the where, and a insert doing just a clustered index insert. Is this simply try to get rid of the repeateable read if not needed, guess have to check with vendor on that or is there a way to get this to not deadlock using repeatable read?

View 2 Replies View Related

Audit Logout, High Reads

May 2, 2007

Hi,

I'm trying to figure out why my sqlserver is flatlined on the CPU. I'm doing a trace and can't help but notice this, with crazy high reads. I'm not sure what this is? It doesnt look good to me, altho maybe its nothing. Any info is much appreciated.

Thanks again!
mike123



Event Class/ TextData/ApplicationName/ LoginName/ CPU/ Reads/ Writes/ Duration

Audit Logout.Net SqlClient Data ProviderloginName3764129784 3146 156

View 3 Replies View Related

Profiler Not Reporting Reads Accurately

Jul 23, 2005

I am running a profiler trace against a database and noticed that thereads column always shows 0. When running the same trace againstanother machine I get back values in the reads column. I took a querythat profiler reported as having 0 reads and ran in in query analyzerwtih STATISTICS IO on and confirmed that there are in fact reads:Table 'tt_cawardalloc'. Scan count 1, logical reads 8, physical reads0, read-ahead reads 1.Table 'tt_clineitem'. Scan count 10, logical reads 125208, physicalreads 1540, read-ahead reads 2995.Table 'tt_contractitem'. Scan count 32, logical reads 676, physicalreads 0, read-ahead reads 0.Table 'tt_contract2'. Scan count 3, logical reads 121, physical reads4, read-ahead reads 0.I am on SQL 2000 sp3a. Any help appreciated.Thanks!

View 8 Replies View Related

Number Of Reads In Profiler Is Not The Same When Running The Same SP On Different PCs

Apr 17, 2007

I'm running the same query on two different PCs and tracing results in Profiler on my PC. When executing the query on PC1 - the total number of reads is 200000. When executing the same query on PC2 - the toal number of reads is 13000. It is almost 15 times more reads when executing query on PC2. The executed query is same on PC1 and PC2. Any reason for this?



I'm trying to analyse that query and reduce the number of logical reads as it's is too high but then I get completly different result on different PC.



Thanks.

View 5 Replies View Related

Checking For Dirty Reads/writes

Apr 17, 2008



Problem Statement........


Lets say user A accesses a record and is making an update to a column... next user B accesses the same record and makes an update to the same column and saves the data... how can user A check to see if an update has been made to prevent overwriting the data..

Is there a query statement that user A can write to check for this?

I understand locking can be used to prevent this but is there an alternative to locking.

View 5 Replies View Related

SQL Profiler: Interprete CPU, Reads, Duration

Jun 2, 2008

I ran Sql profiler and got the following results for a stored procedure

CPU of 1078;
Reads of 125464
writes of 0
Duration of 1882

how do i interpret the above results.
also what CPU and Duration is considered high and indicating a poor performing query.

I am using SQL Server 2005. Thanks

View 4 Replies View Related

Profile Logical Reads Versus STATISTICS IO

May 5, 2015

Why is there often such a dramatic discrepancy between the logical reads recorded in the trace file versus the output of STATISTICS IO?

In the server-side trace I have running I found a reporting procedure that shows having 136,949,501 reads (yes, in hundreds of millions), and it's taking 13,508 seconds to complete.

So I pull the code from the trace and execute it via SSMS - it runs < 1 second, and only generates about 4,000 reads (using various different parameters I get the same result)

The execution plan shows nothing unusual

View 5 Replies View Related

SQL Server 2008 :: Disk Reads And Writes

Nov 5, 2015

How can I measure the disk reads and writes to see if I need to add aditional disks to the server?

View 2 Replies View Related







Copyrights 2005-15 www.BigResource.com, All rights reserved