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Questions tagged [dirtyread]

40 questions
8
votes
3 answers

Dirty Reads in Postgres

I have a long running function that should be inserting new rows. How do I check the progress of this function? I was thinking dirty reads would work so I read http://www.postgresql.org/docs/8.4/interactive/sql-set-transaction.html and came up with…
User1
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1 answer

NHibernate PocoEntityTuplizer is setting entities to "dirty". How do I stop this?

Some of my objects in my database use 0 for a non existent relationship. So I setup a NullableTuplizer class. I found the code for this online. It has worked so far, but I noticed an issue. We have been having major problems with entities being…
BradLaney
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Reading uncommitted changes (dirty read) from SQLite database

I wrote an application (using Qt in C++) which inserts data into a SQLite database. Another application reads data from the same database, but I noticed that it is not possible to read uncommitted data (dirty read). I would like instead to be able…
Luca Carlon
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DB2 syntax (limit and dirty read) when running H2 (in DB2 mode)

I have a few methods that I'm currently trying to unit tests. These methods is running fine (in production) against a DB2 v8 using Spring JdbcTemplates. Each SQL allows "dirty reads" by appending "WITH UR" to the statement. Also, some of them uses…
sunlock
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How does MySQL InnoDB implement Read Uncommitted isolation level

Oracle doesn't allow dirty reads, so Read Uncommitted is not even allowed to be set from JDBC. PostgreSQL also falls back to Read Committed, when choosing Read Uncommitted. SQL Server defines a Read Uncommitted isolation level, because its…
Vlad Mihalcea
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how dirty read works in hibernate

According to Manning's Java Persistence with Hibernate: dirty read occurs if a one transaction reads changes made by another transaction that has not yet been committed. This is dangerous, because the changes made by the other transaction may…
jayendra bhatt
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DB2 Read committed without locking?

We have a transaction that is modifying a record. The transaction must call a web service, rolling back the transaction if the service fails (so it can't commit it before hand). Because the record is modified, the client app has a lock on it. …
Entropy
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Best way to do a "dirty read" of an object that may be locked by another thread in objective-c

I was wondering if the following is the best way to read and make a copy an object that may be locked by another thread? -(NSObject*) getCopyOfActiveObjectsOfType:(Class) objectClass { NSMutableArray* copy = [NSMutableArray…
xcoder
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Dirty read concept in Entity Framework using C#

I am working on Web API using Entity Framework and C#. I need solution for dirty reads. I have tried below method and also transaction method, I need solution for dirty reads. Dirty reads or phantom reads is a phenomenon where a user is not updating…
kusuma rajanna
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Dirty CoW mitigation on CentOS 7.2 - semantic error: while resolving probe point

I am working on implementing a temp patch (non-persistent) on my system as described here (while waiting for the official distro kernel): https://bugzilla.redhat.com/show_bug.cgi?id=1384344#c13 I have tested a dirty copy on write script for the…
Robert J
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When does the value for a rowversion column get updated?

If I have a table with a rowversion column and it gets updated as follows: Name VersionStamp Before update: Bob ABCD After update: Dave EFGH What happens if someone queries the table…
Señor Cardgage
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How to write SQL to Update and void Deadlock?

I need to perform this SQL very frequently UPDATE Users SET UserPoint=UserPoint+(@UserPoint) WHERE UserID=@UserID I can allow dirty-read or dirty-write but I do not want to see deadlock, is there a way to max the chance to avoid deadlock? EDIT OK,…
Eric Yin
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Why does Perl's DBI complain about "Fetch attempted on unopen cursor"?

Here is my script: $db_handle=DBI->connect("$dbstr", "", "", {RaiseError => 0, AutoCommit => 0, PrintError => 1}) || die "Connect error: $DBI::errstr" ; $result=$db_handle->selectrow_array("set isolation to dirty read"); Note: $dbstr is a valid…
kadeshpa
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The impact of using mybatis and hibernate at the same time on the first level cache

If I use both mybatis and hibernate, will there be dirty reads? For example, if I use hibernate to update a certain value and commit, will I read the first-level cache when I use mybatis to read it? Will dirty reads occur?
user14911341
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entity framework - does this do a dirty read?

I have a bit of linq to entities code in a web app. It basically keeps a count of how many times an app was downloaded. I'm worried that this might happen: Session 1 reads the download count (eg. 50) Session 2 reads the download count (again,…
Fidel
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