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| author | Lorry <lorry@roadtrain.codethink.co.uk> | 2012-07-20 20:00:05 +0100 |
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| committer | Lorry <lorry@roadtrain.codethink.co.uk> | 2012-07-20 20:00:05 +0100 |
| commit | 3ef782d3745ea8f25a3151561a3cfb882190210e (patch) | |
| tree | 86b9c2f5fde051dd0bced99b3fc9f5a3ba08db69 /docs/programmer_reference/transapp_why.html | |
| download | berkeleydb-3ef782d3745ea8f25a3151561a3cfb882190210e.tar.gz | |
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diff --git a/docs/programmer_reference/transapp_why.html b/docs/programmer_reference/transapp_why.html new file mode 100644 index 00000000..b8573e72 --- /dev/null +++ b/docs/programmer_reference/transapp_why.html @@ -0,0 +1,93 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <title>Why transactions?</title> + <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> + <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> + <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" /> + <link rel="up" href="transapp.html" title="Chapter 11. Berkeley DB Transactional Data Store Applications" /> + <link rel="prev" href="transapp.html" title="Chapter 11. Berkeley DB Transactional Data Store Applications" /> + <link rel="next" href="transapp_term.html" title="Terminology" /> + </head> + <body> + <div xmlns="" class="navheader"> + <div class="libver"> + <p>Library Version 11.2.5.3</p> + </div> + <table width="100%" summary="Navigation header"> + <tr> + <th colspan="3" align="center">Why transactions?</th> + </tr> + <tr> + <td width="20%" align="left"><a accesskey="p" href="transapp.html">Prev</a> </td> + <th width="60%" align="center">Chapter 11. + Berkeley DB Transactional Data Store Applications + </th> + <td width="20%" align="right"> <a accesskey="n" href="transapp_term.html">Next</a></td> + </tr> + </table> + <hr /> + </div> + <div class="sect1" lang="en" xml:lang="en"> + <div class="titlepage"> + <div> + <div> + <h2 class="title" style="clear: both"><a id="transapp_why"></a>Why transactions?</h2> + </div> + </div> + </div> + <p>Perhaps the first question to answer is "Why transactions?" There are +a number of reasons to include transactional support in your applications. +The most common ones are the following:</p> + <div class="variablelist"> + <dl> + <dt> + <span class="term">Recoverability</span> + </dt> + <dd>Applications often need to ensure that no matter how the system or +application fails, previously saved data is available the next time the +application runs. This is often called Durability.</dd> + <dt> + <span class="term">Atomicity</span> + </dt> + <dd>Applications may need to make multiple changes to one or more databases, +but ensure that either all of the changes happen, or none of them +happens. Transactions guarantee that a group of changes are atomic; +that is, if the application or system fails, either all of the changes +to the databases will appear when the application next runs, or none of +them.</dd> + <dt> + <span class="term">Isolation</span> + </dt> + <dd>Applications may need to make changes in isolation, that is, ensure that +only a single thread of control is modifying a key/data pair at a time. +Transactions ensure each thread of control sees all records as if all +other transactions either completed before or after its transaction.</dd> + </dl> + </div> + </div> + <div class="navfooter"> + <hr /> + <table width="100%" summary="Navigation footer"> + <tr> + <td width="40%" align="left"><a accesskey="p" href="transapp.html">Prev</a> </td> + <td width="20%" align="center"> + <a accesskey="u" href="transapp.html">Up</a> + </td> + <td width="40%" align="right"> <a accesskey="n" href="transapp_term.html">Next</a></td> + </tr> + <tr> + <td width="40%" align="left" valign="top">Chapter 11. + Berkeley DB Transactional Data Store Applications + </td> + <td width="20%" align="center"> + <a accesskey="h" href="index.html">Home</a> + </td> + <td width="40%" align="right" valign="top"> Terminology</td> + </tr> + </table> + </div> + </body> +</html> |