Tagged Questions

A mechanism for committing a consistent set of changes into a database atomically.

learn more… | top users | synonyms

1
vote
2answers
82 views

Transaction basics. What is the result of 2 transactions running concurrently?

I have a rather basic question on transactions. Assume a table Account with a column amount. Now we have the following code: BEGIN $amount = SELECT amount FROM ACCOUNT WHERE id = 123; $amount = ...
1
vote
1answer
215 views

What happens to a transaction if the network connection fails?

What happens to a transaction when the client connection is lost. Example the client is a web application code that starts a transaction to a remote server instance. The client sends the sql code to ...
1
vote
0answers
52 views

Is there a way to detect if there is an uncommitted transaction in H2?

I am using an H2 database with JDBC to create a connection with setAutoCommit(false). I am currently programatically checking whether or not there is an uncommitted transaction, but I was wondering ...
0
votes
0answers
48 views

About transactions on mongodb

To what extent the atomic storage of mongodb can leave your database unsafe of inserts or updates on my data? In the other words. What are the possibilities of my data not been (inserted or updated) ...
0
votes
1answer
90 views

Case of irrecoverable error in transaction

According to an exam question,which may lead to an irrecoverable error: 1.A transaction writes a data item after it is read by an uncommitted transaction. 2.A transaction a data item after it is ...
0
votes
2answers
225 views

DB2 - How to get value for: Transation Per Minute parameter for DB?

Hi is there some easy way to find out what is transaction per minute value for the database? Should I use db2 get snapshot? We are using DB2 9.7 ESE on Linux Thank you in advance
1
vote
1answer
226 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 ...
2
votes
1answer
62 views

SSIS Transaction Level for Single Task

I have 3 tasks in a SSIS package. If the final task fails I only want that task to rollback. Do I just set that task to REQUIRED? Or leave it as SUPPORTED? Thanks!
11
votes
5answers
222 views

What is the exact relationship between a database transaction and locking?

This is a humble question asked in the spirit of increasing my knowledge; kindly be gentle in your response. As a long-time application developer, I know at some level what a transaction is (I use ...
3
votes
2answers
322 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
129 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 ...
0
votes
0answers
816 views

Oracle Transaction recovery: lock conflict caught and ignored

In alert log there are a lot of "Transaction recovery: lock conflict caught and ignored" statements. I've found some information, that this error is caused when there is an active dead transaction. ...
-1
votes
1answer
286 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
2k views

statistics State in MySQL Processlist

I have a busy MySQL Server having query SELECT sys_sess_state, index_state, timeout_lvl, last_queued_dt, last_polled_wait_dt, create_id, create_dt, modify_id, modify_dt FROM PQR_AM_SYSTEM_SESSION ...
1
vote
2answers
331 views

MySQL - INSERT … SELECT .. FROM .. - Single transaction or transaction per row?

Question: I am currently working on a data migration. I need to migrate 2.5 million rows from one InnoDB table to another InnoDB table (with a different setup). I am using the following syntax to do ...
1
vote
1answer
78 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 ...
8
votes
1answer
395 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 ...
7
votes
3answers
257 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
104 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
91 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 ...
7
votes
1answer
400 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
230 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- ...
0
votes
1answer
148 views

Should I use begin tran to do an alter table column that increases the column length?

I want to execute this statement in a production database to alter the length of a varchar column from 50 to 72: ALTER TABLE Users ALTER COLUMN LoginID varchar(72) NOT NULL The column is not null ...
2
votes
1answer
56 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 ...
1
vote
2answers
212 views

Oracle - Is it possible to maintain transaction across multiple schemas?

I got this database in oracle which includes 4 schemas. Each schema represents a logical layer. Each transaction (Stored Procedure) in the upper layer breaks into a couple of transactions in the lower ...
0
votes
0answers
118 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 ...
2
votes
1answer
123 views

What is the standard isolation level for a db used for money data?

When using a database server for monetary/financial data, I can only assume that using transactions is mandatory. But what I am not sure is which is usually the isolation level? Is a READ-REPEATABLE ...
0
votes
0answers
68 views

MySQL server vs client isolation levels

What is the difference between setting the transaction isolation level in the client configuration and the server configuration? If I set the client isolation level to be serializable while the ...
3
votes
1answer
946 views

Why can't I change the isolation levels of my connection in MySQL?

I am trying to experiment a bit with the isolation level of MySQL in a test environment. I do the following: mysql> set @@session.tx_isolation='READ-UNCOMMITED'; ERROR 1231 (42000): Variable ...
0
votes
1answer
82 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
107 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
398 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 ...
2
votes
0answers
102 views

Why does MySQL force the tradeoff between swallowing errors and leaking commits in transactions?

Referring specifically to the choice of whether to use DECLARE EXIT HANDLER FOR SQLEXCEPTION. If you use it, you swallow errors and there doesn't seem to be any way to access them programmatically, ...
2
votes
1answer
331 views

Using the auto increment id from one query as the fk of the next insert

I'm not sure if I'm overcomplicating this or whether I can't see the wood for the trees. I have two tables, both have auto incrementing ID's. Table 1: ID - auto field - int other field - varchar ...
0
votes
1answer
2k views

Uncommitable T-SQL transaction after trigger applied to table

Good morning, I have written a Trigger on a table that should evaluate the entered values (Length, width and Height) and based on those entered values, should update a column (Type) in the same record ...
0
votes
1answer
623 views

How to avoid locks by large transactions?

We have a large application running, that requires cleanup for performance reasons. This was however not forseen when designing the application. Basically, the delete is executed from a stored ...
4
votes
1answer
448 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
84 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.
3
votes
1answer
402 views

Complex constraint across all data in a table

We have a table to record processing that occurs on a system and we need to ensure that only a single row has an 'in process' status. I want to ensure that the result of this is always either zero or ...
1
vote
1answer
399 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 ...
1
vote
1answer
401 views

postgres+JDBC: fire trigger with non autocommit transaction

i have a jdbc client that make an two INSERT query on database whitout autocommit, and a trigger on database that fires when a insertion is done on a certain table public foo() throws MyException { ...
0
votes
1answer
1k views

Putting a Select statement in a transaction

What is the difference between these 2 queries: start transaction; select * From orders Where id=1; UPDATE orders SET username="John" Where id=1; commit; And without transaction: select * From ...
7
votes
3answers
866 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
0answers
49 views

Federate engine to help overcome distributed transaction?

Currently we have been using pure innodb. The issue is that we have architecture where we have multiple outlet each have its own local db and a copy of it in the hq outlet. The issue is that we ...
0
votes
2answers
252 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 ...
18
votes
2answers
5k 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
3k 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
638 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
722 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 ...
4
votes
3answers
5k views

sleeping SPID blocking other transactions

I'm really having trouble tracking down some blocking we are experiencing. The root blocking SPID's status is 'sleeping', the cmd is 'AWAITING COMMAND', and the sqltext is 'SET TRANSACTION ISOLATION ...