Questions tagged [isolation]
258 questions
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Why is it a "lost update" in the Read Committed Transactions example of Oracle documentation?
In the book "Oracle Database Concepts", Oracle gives an example to explain Read Committed Isolation Level.
In the example, transaction 1 updates row 1, then transaction 2 updates the same row before transaction 1 commits. So, transaction 2 waits…
Fang Zhen
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Change isolation level with Spring 4.0 & Hibernate 4.2.8
we are developing an app with Spring 4.0.0, Hibernate 4.2.8 and Ms SQL Server 8, which uses a custom sequence backed with a DB table and mapped with a Hibernate VO (CustomSequence)
This sequence is accesed within a service call:
Main service…
pollytronman
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Need Design & Implementation inputs on Cassandra based use case
I am planning to store high-volume order transaction records from a commerce website to a repository (Have to use cassandra here, that is our DB). Let us call this component commerceOrderRecorderService.
Second part of the problem is - I want to…
Santanu Dey
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why mysql queries takes table lock in isolation read uncommitted?
Is there any way to get mysql queries to not take any locks on myisam tables?
My problem seems to be that my Sphinx Search indexer takes a lock on one of my myisam tables for over 60s which seem to make update statements wait on the locks to be…
Peder
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Abstract base classes and appdomains
I apologize now if my upcoming explanation doesn't make enough sense; I'm reknown for it, though I try to do otherwise.
I'm writing a service that makes use of user-defined plugins. I'm trying to isolate them -- keeping their assemblies out of the…
redman
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How to enable read committed snapshot only
I'd like to use READ COMMITTED SNAPSHOT in a SQL Server database, which I understand is different from SNAPSHOT ISOLATION.
I want to enable READ COMMITTED SNAPSHOT because I'm having problems with deadlocks. I'm using EF and I think this will…
xrodas
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Running library in isolation
I started working in a DI framework (just for fun) a few weeks ago, and while building it I came across the following issue. Basically most of us are concern about using DI frameworks so that we code against interfaces rather than implementations,…
MeTitus
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Cassandra atomicity/isolation guarantee in repair modes
I know that Cassandra offers atomicity and isolation for batch mutations on row-level basis since version 1.1 (http://www.datastax.com/dev/blog/row-level-isolation)
But do these guarantees also hold for all the repair mechanisms (hinted handoff,…
snd
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Bypass windows session isolation, display warning message in user session from system service, windows 7+
I am looking to implement a feature when an application running as a windows service (as localsystem) will display a modal warning, something similar to a shutdown screen or UAC warning screen. Basically, something that is impossible to dismiss…
galets
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mysql isolation levels
I'm a bit confused by the documentation here. I have a transaction, which
start transaction
does some updates
does some selects
does some more updates
commit
I want my selects at step 3 to see the results of updates in step 2 but I want to be…
Igor Serebryany
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Architecture Isolation mechanisms
We are currently reviewing how to isolate our core business components (in the code) from the front end development. We already have multi-tier architecture but they are referenced using dll (or webservices in some places).
What we would like to do…
activebiz
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Using Rails model that is already declared
Declaring a class for (fast) testing purposes is great:
require 'fast_helper'
require 'site_search'
class Post; end # This allows not to load the whole Rails env
describe SiteSearch do
it "searches on posts" do
Post.stub_chain(:scoped,…
Dmytrii Nagirniak
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Which isolation mode should you choose if you want the least concurrency?
If you need to minimize concurrency as much as possible, which isolation level (repeatable read, serializable, read committed, read uncomitted) would work best?
Pan
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Properly testing an API wrapper for Recurly
I'm thinking about the way that I can test this class, its interface only exposes two methods, add_property and remove_property which just wrap the Recurly API.
class SubscriptionManager
def initialize(account_code)
@account_code =…
TheDelChop
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Does Mongo ensure isolation when updating single documents?
The Mongo documentation on atomicity and isolation is a tad vague and slightly confusing. I have this document structure and I want to ensure mongo will handle updates while isolating updated from different users.
Assume a collection of product…
raffian
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