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

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1
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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.
2
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1answer
184 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
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1answer
169 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
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1answer
216 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
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0answers
96 views

calculate Transaction per Second on mysql ndbcluster

what is the formula to calculate the TPS of mysql ndbcluster? for example i have 5 clients to submit 200 queries each client.
0
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1answer
309 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 ...
6
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3answers
339 views

Get transactions that failed or were never committed

Is there anywhere I can look to find failed transactions in SQL server 2012?
0
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0answers
48 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
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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
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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
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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
353 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
291 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
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3answers
2k 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 ...
0
votes
1answer
800 views

Lock wait time out exceed restart transaction

I had got error on the lock wait time out so below I got 3 samples taken. One I took before the increase innodb_lock_wait_timeout to 120. So is there anything else I must tweak based on the logs ...
1
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2answers
294 views

Read Committed Isolation Level

Quote from docs: Read Committed is the default isolation level in PostgreSQL. When a transaction uses this isolation level, a SELECT query (without a FOR UPDATE/SHARE clause) sees only data ...
1
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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
99 views

How do I stop a query from running if the row is locked?

I have a section of code that locks the database, updates it and then confirms. This is all working fine, if another user attempts to update the same row they cannot and their changes are discarded. ...
0
votes
1answer
360 views

postgres deadlock without explicit locking

I use PostgreSQL 9.2, and I do not use explicit locking anywhere, neither LOCK statement nor SELECT ... FOR UPDATE. However, recently I got ERROR: 40P01: deadlock detected. The query where deadlock ...
0
votes
1answer
141 views

Database atomic operations implementation

The question is about queries that are not wrapped in 'begin-commit' block, but about plain inserts and updates that are atomic in PostgreSQL, MySQL (innodb engine at least). So how is this ...
4
votes
2answers
571 views

Transactions, references and how to enforce double entry bookkeeping? (PG)

Double entry bookkeeping is a set of rules for recording financial information in a financial accounting system in which every transaction or event changes at least two different nominal ...
2
votes
1answer
529 views

unique constraint violated (ORA-00001) in concurrent insert [closed]

I have a procedure that is called from concurrent transactions: //Some actions here INSERT INTO table1 (table1_id, table1_val1, table1_val2, table1_val3) VALUES ...
1
vote
1answer
105 views

Does PostgreSQL optimize queries in transaction?

In my app I need to make big imports from user files, and to achieve that all records are updated/created I do it inside transaction. But before it I need to update massive, already existing in DB, ...
0
votes
1answer
302 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
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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
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0answers
44 views

Examples of a database with no consistency measures that ensures consistency through schema alone

To clarify, the database can be any type RDBMS, NoSQL/BigTable. However, it must not employ any usual consistency measures such as locks, or synchronization, but the inconsistency-invincibility must ...
0
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0answers
75 views

What would this non-'unique index with a unique search condition` query lock?

I am not sure about this part of the transaction manual For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), UPDATE, and DELETE statements, locking depends on whether the statement ...
1
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2answers
86 views

Do I need a locking read?

I am inserting rows in a table, based on a value and on the existence of a row, which I get from SELECT statements. This function can be run concurrently, so I need to do some extra obviously. The ...
1
vote
1answer
171 views

Postgresql Two-phase Commit Transaction Identifier

Is it possible to perform a two-phase commit in Postgresql when the databases exist on the same server? As a simple test, I would connect to the first database and run: BEGIN; PREPARE TRANSACTION ...
1
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2answers
150 views

Are MySQL transactions under-utilised?

I have a vague understanding of transactions that it means you can help the server understand that a series of queries are related. Scenario : Suppose I have a series of queries which creates a user ...
0
votes
1answer
558 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
101 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 ...
2
votes
1answer
173 views

How to scale MySQL transaction wrapped queries?

So I'm working on an app that wraps many of it's SQL queries in a transaction for it's SQL usage and I'm trying to think of some ways to scale the DB layer up.... Up until now we've been throwing ...
1
vote
1answer
969 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 ...
3
votes
1answer
172 views

SQL Server 2008 - Adding a column and a filtered index within a single transaction?

This is more of a general question. Why can you not add a filtered index within the same transaction scope as adding the new column in the first place? The solution is of course simple, just make two ...
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 ...
4
votes
2answers
224 views

Delete all rows within transaction: what would happen to other transactions?

I currently have a function in PostgreSQL that creates a temp table, fills it, performs some tricky selects and returns results. postgresql's temp tables are local to functions, so this helps me avoid ...
3
votes
1answer
2k views

Deleting MySQL table with pending transactions

Is there a way to delete an InnoDB table or database with pending transactions in MySQL (preferably on file system level)? What happened: I use MySQL 5.5.28 and ran LOAD DATA INFILE… to import a ...
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 ...
0
votes
1answer
321 views

jdbc: does setAutoCommit(true) commits past executions?

I would like to execute some statements, and commit the entire batch at the end. I've tried the following approach: connection.setAutoCommit(false); // Don't commit for each statement ...
2
votes
2answers
3k views

Table Lock on INSERT - How to optimize

we have a few long running procedures in the database, that cause an instant Table Lock on our main text storage table, which causes all other requests of the web app to wait (because the table is ...
2
votes
1answer
282 views

Add user to Server Role in a transaction

Situation One webapp responsible for creating other webapps using SQL Server 2008 R2 Stored Procedures. One of the steps in creating another webapp is creating a new database, a login/user, assigning ...
3
votes
2answers
825 views

How do I implement insert-if-not-found for transactions at serializable isolation level?

I'm having a hard time figuring out how to exactly implement a 'insert if not found' function. Consider the following. We have a table called artist with 2 columns, (name, id) where name is the ...
2
votes
1answer
448 views

Rollback generate scripts

During the development of applications users often want to add new modules, business rules etc. So I've often used SQL Server 2008 option to create scripts from the development DB to generate new ...
0
votes
1answer
315 views

MYSQL MyISAM data recovery implementation

I am creating integration into eshop script, shop is using MyISAM tables and I need to implement something like transactions in InnoDB, what I actually need is full recovery of data after modifying or ...
1
vote
0answers
89 views

migrations within transactions

I have a bash script to run migrations on our MySQL databases. Is it possible to wrap migrations within a single transaction when running multiple migration scripts from the command line? ...
1
vote
1answer
516 views

Does TRANSACTION/COMMIT/ROLLBACK only work on certain MySQL engines such as InnoDB?

Are transaction functions only relevant for particular database engines on MySQL, or are transactions supported under all MySQL engines, including MyISAM and InnoDB? someone says here that ...
4
votes
3answers
923 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 ...