0
votes
0answers
42 views

When is transaction removed from sys.dm_tran_active_transactions?

We are having some issues with clients getting Transaction Timeout when connecting to our clustered SQL Server 2008 R2. To investigate the problems I have been digging into ...
1
vote
1answer
119 views

DB Locks - How would one handle long transactions and maintain high concurrency?

We're maintaining a POS/WMS Application built in powerbuilder that runs on SQL Server 2008 R2 backend. Recently, we've been having a lot of locking issues and I believe it has to do with how we handle ...
3
votes
2answers
142 views

T-SQL - Enforce Atomic Operations x Locks

I have a database model that works similar to a banking account (one table for operations, and a trigger to update the balance). I'm currently using SQL Server 2008 R2. Table OPERATIONS: VL_CREDIT ...
0
votes
1answer
83 views

What causes lost updates being observed in my SQL Azure database?

I have a SQL Azure database with the following tables: CREATE TABLE [dbo].[UserBalances] ( [UserId] UNIQUEIDENTIFIER UNIQUE NOT NULL DEFAULT NEWID(), [AvailableMoney] INT NOT NULL ...
-1
votes
1answer
99 views

default value with select case on xml

select case 'NULL' when 'NULL' then 'f' end as out output: f but select case (select (SELECT LEFT(l.list,LEN(l.list)-1) FROM (SELECT o.Reciting_Path + '|' + o.Declaimer +',' AS [text()] ...
1
vote
1answer
50 views

How, when and why does implicit changing of transaction isolation level happen?

RCSI (Read Committed Snapshot Isolation) is the setting of a database changing the behavior of (the default) Read Committed isolation level in SQL Server. This is, as I understand, the context of ...
7
votes
1answer
126 views

In case of multiple updates of the same record in a single transaction, how many versions are being stored?

According to MSDN article by Kimberly L. Tripp, Neal Graves's "SQL Server 2005 Row Versioning-Based Transaction Isolation "... All the earlier versions of a particular record are chained in a linked ...
6
votes
2answers
91 views

“When a connection is closed and returned to the pool, the isolation level from the last SET TRANSACTION ISOLATION LEVEL statement is retained”?

The MSDN online article "Snapshot Isolation in SQL Server" states: "An isolation level has connection-wide scope, and once set for a connection with the SET TRANSACTION ISOLATION LEVEL statement, ...
3
votes
1answer
81 views

Why do row-versioning isolations use a linked list of versions of record? [closed]

Trying to better understand row-versioning based transaction isolations in SQL Server... According to Kimberly L. Tripp, Neal Graves's "SQL Server 2005 Row Versioning-Based Transaction Isolation": ...
6
votes
1answer
67 views

Does RCSI use less or same space than SNAPSHOT? Why?

Trying to better understand row-versioning based transaction isolations - RCSI (Read Committed Snapshot Isolation and SNAPSHOT) - in SQL Server... MSDN online article "Choosing Row Versioning-based ...
6
votes
1answer
203 views

Specific TempDB insert of UserDB select results in SOS_SCHEDULER_YIELD to ENCRYPTION_SCAN

One of our production systems has exhibited a problem with a single insertion statement into a temp table from our user database. When I comment out the insert/select, the stored proc in question runs ...
0
votes
1answer
72 views

Can we set LOCK_TIMEOUT instance- or database-wide?

It is possible to change the SQL Server's default (which is -1 or indefinite period of time) LOCK_TIMEOUT value session-wide. Is it possible to set LOCK_TIMEOUT default value server-, instance- ...
2
votes
1answer
51 views

Why - read but not update ops fail in case of lacking space in tempdb database?

MSDN online article "Choosing Row Versioning-based Isolation Levels" states: "tempdb must have enough disk space for the version store. If there are very long-running transactions, all the ...
0
votes
0answers
71 views

What are the possible reasons for SQL Server errors on reading operations upon switching ALLOW_SNAPSHOT_ISOLATION` and `READ_COMMITTED_SNAPSHOT ON?

I have a client-server app running in Windows Server 2008R2 using/interacting SQL Server 2012. After reading app's documentation as well as feedbacks on internet from those who already accomplished ...
0
votes
1answer
59 views

SQL Server Transaction Log File [duplicate]

I am currently in an live environment and I am trying to clear some disk space. I noticed that a SQL Server database transaction log file is kinda big (12GB). The recovery model of that database is ...
0
votes
2answers
94 views

Does ROLLBACK TRAN honor LOCK_TIMEOUT value?

I have a following stored procedure on my system. BEGIN TRY BEGIN TRAN SET LOCK_TIMEOUT 10000 UPDATE tbl COMMIT TRAN END TRY BEGIN CATCH IF @@TRANCOUNT > 0 ROLLBACK TRAN END CATCH ...
0
votes
1answer
248 views

connection pooling, transactions, nested transaction and rollback

I've got strange behavior on production. First user request thru application failed, I've got SQLServerException with "Lock request time out period exceeded." After that following requests are ...
4
votes
1answer
211 views

Locking in “Read Committed Snapshot”

If an update is run on a table with "Read Committed Snapshot" isolation level and a commit is pending eg: update table1 set col1 = col1 + 1 where PKcol < 3 update table1 set col1 = col1 + 1 ...
1
vote
2answers
71 views

Read committed snapshot:Finding lock on table

IF update command is run on a table and commit is pending then another user cannot be able to update the table. Is there any query to get the user or PC which caused lock on the table.
1
vote
1answer
170 views

Distributed - across multiple databases or servers - Transactions

I have some doubts related to transactions in SQL. I perform below steps. Connection 1 open for DB1 database Begin transaction for Connection 1 Run the commands on Connection 1 Connection 2 open for ...
6
votes
3answers
341 views

Get transactions that failed or were never committed

Is there anywhere I can look to find failed transactions in SQL server 2012?
0
votes
2answers
165 views

Shrink transaction log while transaction in progress

I have a several-GB import into my SQL Server 2005 (Standard Edition) database. The import is separated into 4 parts, each part in its own transaction. As you can guess, the transaction log files ...
11
votes
2answers
2k views

Is it a bad practice to always create a transaction?

Is it a bad practice to always create a transaction? For example, it is a good practice to create a transaction for nothing but one simple SELECT? What is the cost of creating a transaction when it ...
0
votes
2answers
1k views

Linked Servers pointing to same server (localhost) causing “Transaction context in use by another session” error

We are using SQL Server 2008. Normally our app that is using different databases distributed over the network and some of the stored procedures we call therefore make use of linked servers. Now I ...
2
votes
2answers
355 views

Partial rollback doesn't decrement trancount

Suppose I have an open SQL Server session, and do the following: begin tran insert into People (Id) values (1) select @@TRANCOUNT -- Prints 1 save transaction tt begin tran select @@TRANCOUNT ...
2
votes
2answers
292 views

How to rollback the identity seed after deadlock

Now that's an approximate sequence of operations Im performing: SET IDENTITY_INSERT <table-name> ON; INSERT SOMETHING to <table-name> with explicitly specifyed id DECLARE @oldID bigint ...
1
vote
0answers
33 views

Does SQL Server place shared locks on scanned records when using REPEATABLE READ [duplicate]

Assume a SQLCmd session which is using transaction isolation level REPEATABLE READ. In this session I start a transaction and execute an UPDATE statement with a WHERE clause on a non indexed column. ...
0
votes
1answer
303 views

Query notifications and connection options

I'm investigating a problem with query notifications. The platform is SQL Server 2008 R2 (SP1) - 10.50.2500.0 (X64) Standard Edition. .NET errors show a problem reported from SqlNotificationInfo ...
5
votes
1answer
2k views

Trigger in combination with transaction

Suppose we have the following situation: We have a table (let's say Table_A), wich has a trigger on INSERT. The trigger job is to update some rows in table_B based on the inserted values in table_A. ...
0
votes
1answer
560 views

Does TRUNCATE TABLE affects isolation level in Sql Server?

As I am working on the project which has SQL SERVER as a database....I'm maintaining isolation level in my project where I enabled snapshot isolation level for my project.... As I have to make some ...
1
vote
1answer
102 views

Does a transaction cover the subroutines?

When I begin transaction and exec a stored procedure, does that transaction cover the changes made by the stored procedure I executed? Would a rollback transaction cancel the changes made by the ...
1
vote
1answer
275 views

Commit Insert but Hold Lock

I have implemented what is effectively a reliable queue through the following: CREATE TABLE Queue (MessageID UNIQUEIDENTIFIER, Message varchar(255)) --Enqueue Command DECLARE @MessageID ...
1
vote
1answer
976 views

SQL Server - how transactions and transaction log work (simplified)

I have a theory on how transactions work, but I would like if someone could verify it or correct some points if possible. Let's consider we have a database with full recovery model. Now, everything ...
4
votes
2answers
2k views

Transaction and Try-catch in SQL Server Job

We have DML operations in each step of a SQL Server job. To ensure the update/insert will be rolled back in case something goes wrong, I have wrapped the data modifications of each step in TRY CATCH ...
9
votes
1answer
2k views

SQL query for combinations without repetition

I need a query which can be used in (or as) a function and retrieves all combinations of n values. And I need all combinations of length k where k = 1..n. Extended sample input and result so input ...
2
votes
1answer
129 views

Transaction level difference between using a large IN filter VS. “BEGIN TRAN/COMMIT”

I would like to delete about 100,000 records with minimal server overhead. I've had a few nagging questions I haven't been able to test properly so I figured I'd ask some experts here. Which would ...
4
votes
3answers
932 views

Can I change table structure in a transaction and then roll it back if there is an error?

I have some ALTER TABLE statements that I am running. Not all of them work (they are the result of running SQL Data Compare) and I want to group them in some transactions and roll back the statements ...
3
votes
1answer
206 views

SQL Server : KEY lock prevents FK on nearby row, but not SELECT [closed]

I have the following table structure (simplified, pseudocode): TABLE dbo.Users (Id int NOT NULL IDENTITY PRIMARY KEY) TABLE dbo.Transfers ( Id int NOT NULL IDENTITY PRIMARY KEY, ...
3
votes
2answers
2k views

Will a delete then insert within a transaction cascade?

I had a question about what the expected and actual behaviour for the following scenario is. The scenario is one where a database table ([table1]) is cleared and reloaded every day. The table has an ...
3
votes
3answers
494 views

Why am i getting deadlocks with 1 read and 1 write thread in SQL

if anyone could please help me understand why the following transactions deadlock? I am providing the 2 transactions and the indexes for each table: Transaction 1: SELECT blockId, blockData, ...
1
vote
2answers
165 views

INSERT statements in a transaction and locking a range of rows

I have a table that is concurrently accessed by many users. Typically, INSERTs to the table are made one at a time. Occassionaly, users will add a "batch" of rows at the same time. The batch is ...
5
votes
1answer
197 views

Triggers and the Transaction

We recently made a change to create constraints based on logic previously used in stored procedures, and part of that included the use of INSTEAD OF triggers to centralize logic. The logic is ...
3
votes
2answers
2k views

What server property makes TransactionScope escalating to MSDTC?

In our application we're using TransactionScope's. We're aiming to not use the MSDTC service because it's a lot slower than lightweight transactions. using (var transactionScope = new ...
5
votes
1answer
180 views

Does the transaction isolation level affect indices as well?

Here's one for the SQL Server gurus: if I set my SQL Server 2008 transaction isolation level to READ UNCOMMITTED, does that also affect the index pages? E.g. using ISOLATION LEVEL READ UNCOMMITTED, ...
0
votes
1answer
1k views

how to make a table unlocked within transaction block

I am using SQL Server 2008. I have several stored procedures that process different reports. Each stored procedure makes use of Begin Transaction' and 'Commit Transaction, using the default ...
1
vote
2answers
793 views

SQL Server 2008 R2 - How to check Foreign Key constraints in a transaction only when committed?

We are synchronizing tables between two databases (yes, it needs to be done by our software and not by replication etc.) Both databases are identical with many foreign-key constraints on tables. ...
3
votes
1answer
243 views

Does blocking always mean open transaction?

This may seem a bit dull question but does blocking always mean that there is open transaction and that may cause transaction log grow to infinity because open transaction prevents log truncation ...
6
votes
3answers
2k views

SQL Server - what isolation level for non-blocking select statements?

I have a long running transaction (called, say, T1) that performs some deletes, updates and inserts on a table in SQL Server 2008 R2. At the same time, another process periodically runs select ...
20
votes
3answers
14k views

What risks are there if we enable read committed snapshot in sql-server?

I have read here that some extra data will be stored per row so we might see a performance degradation but what other risks are there? eg. Will this affect recovery of the database? Is there anything ...
3
votes
1answer
211 views

Is SQL Server Replication transactionally 'safe' across all published tables?

We have a system that has one of its datasources still on SQL Server 2000. In order to achieve higher availability, we are looking to setup transactional replication from this 2000 server to a 2008 ...