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

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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
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1answer
72 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
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1answer
363 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
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3answers
205 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
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1answer
99 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
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1answer
84 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
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1answer
333 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
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1answer
163 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
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1answer
130 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
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1answer
54 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 ...
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0answers
190 views

Two-phase commit in MongoDB

I read the online document here and for hours of researching and trying things out I still have a question need explanation. The documentation says that there are two classes of failures, which for ...
1
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2answers
185 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
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0answers
102 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
120 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
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0answers
67 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 ...
0
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0answers
27 views

Transactions' order of commitment within Serializable schedules

The following diagram was taken from a book(T1 and T2 are transactions which read and write to databases objects A and B). For convenience, I quoted few lines of text in that book which describe the ...
3
votes
1answer
763 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
77 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
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2answers
104 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
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1answer
339 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
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0answers
95 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
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1answer
246 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 ...
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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
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1answer
527 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
388 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
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2answers
83 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
342 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
343 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
353 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 ...
6
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3answers
686 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
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
215 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 ...
15
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2answers
4k 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
2k 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
541 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
606 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
4k 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
1k 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
vote
2answers
528 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
34 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
128 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
643 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
235 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
915 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
656 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
108 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
456 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 ...
10
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1answer
4k 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
46 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 ...