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1answer
76 views

What are the considerations when using SERLIALIZABLE over READ COMMITTED isolation level in Oracle?

What are the considerations when using SERIALIZABLE isolation level over the default READ COMMITTED in an Oracle database? Given the concurrency system used within Oracle (using transaction logs to ...
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1answer
341 views

Sybase ASE lock table to disallow users insert values

I need to disallow users to insert values in some table, for example for a 5 mins. Seems I should use at isolation clause but can't figure out how to use it. Thanks
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0answers
36 views

SQL Server Performance : isolate different databases under same engine

I have SQL Server 2014 installed onto a machine with two different users and two catalogs, each of them accessed by a different user (each user is strictly tied to his catalog). Is it possible that a ...
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0answers
111 views

debugging PostgreSQL serialization failures

I am trying to migrate our PostgreSQL 9.4 database from transaction level READ COMMITTED to either REPEATABLE READ or SERIALIZABLE. In either case, I'm exposed to a new set of errors with the format: ...
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0answers
31 views

MySQL - Transactions and causality

I'm new to MySQL's LOCK and TRANSACTION and have a question about different isolation levels of a transaction: Given two transactions executing the same code (auto-commit is false): (1) get data of ...
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0answers
138 views

Transactions using Isolation Level on databases with FileStream

We have a highly transactional application. We have a requirment to upload huge data into our database that can happen for a duration of 5-10 minutes. During our upload time, the tables are getting ...
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0answers
34 views

How system resolves when particular resource lock at uncommitted transaction

Let us assume Transaction T1#: Initiated on 2015-10-30 10:25:41.380 Transaction T2#: Initiated on 2015-10-30 10:25:41.580 The above two transactions are initiated through application. T1# & ...
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0answers
22 views

Does DB2 for z/OS have isolation level similar to READ ONLY in Oracle?

Does DB2 for z/OS have isolation level similar to READ ONLY in Oracle? I need to implement several big selects to DB2 and also I need to retrieve consistent data which was commited on time when ...
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0answers
33 views

Can a slow SELECT statement in READ COMMITTED isolation level read content from concurrent committed UPDATE?

Let's say we have a big table with hundreds of million of rows (or more). On one connection, we perform a query requiring full table scan under READ COMMITTED isolation level: SELECT * FROM ...
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0answers
220 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 ...
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0answers
78 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 ...
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0answers
150 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 ...