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Summary

Transactions are an integral part of any relational database. You control transactions through a ColdFusion application by using the <cftransaction> tag. This tag has no required attributes but controls isolation levels through the isolation attribute, and can conditionally commit or roll back parts of a transaction through the action attribute. Transactions cannot be spanned across pages.

Sample Questions

1:Which of the following statements are true?
  1. The <cftransaction> tag can control isolation levels.

  2. Isolation levels affect performance.

  3. Isolation levels affect locking.

  4. ColdFusion enforces isolation when a database does not.

2:What is the primary purpose of <cftransaction>?
  1. To commit all inserts to the database

  2. To make sure dirty reads do not take place

  3. To support commit and rollback features of a relational database system

  4. To supplement the <cflock> tag in locking database records

3:What is wrong with the following code?
<cftransaction>
 <cfquery datasource....> ... </cfquery>
 <cftransaction action="commit">
</cftransaction>

  1. Commits must be performed in a <cfif> block.

  2. Inner <cftransaction> is not terminated.

  3. Transaction tags can't be nested.

  4. Queries must be performed after commits are executed.

4:Which isolation level is the least efficient?
  1. serializable

  2. repeatable_read

  3. read_uncommitted

  4. read_committed


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