diff options
Diffstat (limited to '')
-rw-r--r-- | www/c3ref/snapshot.html | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/www/c3ref/snapshot.html b/www/c3ref/snapshot.html new file mode 100644 index 0000000..4a99b00 --- /dev/null +++ b/www/c3ref/snapshot.html @@ -0,0 +1,154 @@ +<!DOCTYPE html> +<html><head> +<meta name="viewport" content="width=device-width, initial-scale=1.0"> +<meta http-equiv="content-type" content="text/html; charset=UTF-8"> +<link href="../sqlite.css" rel="stylesheet"> +<title>Database Snapshot</title> +<!-- path=../ --> +</head> +<body> +<div class=nosearch> +<a href="../index.html"> +<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0"> +</a> +<div><!-- IE hack to prevent disappearing logo --></div> +<div class="tagline desktoponly"> +Small. Fast. Reliable.<br>Choose any three. +</div> +<div class="menu mainmenu"> +<ul> +<li><a href="../index.html">Home</a> +<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a> +<li class='wideonly'><a href='../about.html'>About</a> +<li class='desktoponly'><a href="../docs.html">Documentation</a> +<li class='desktoponly'><a href="../download.html">Download</a> +<li class='wideonly'><a href='../copyright.html'>License</a> +<li class='desktoponly'><a href="../support.html">Support</a> +<li class='desktoponly'><a href="../prosupport.html">Purchase</a> +<li class='search' id='search_menubutton'> +<a href="javascript:void(0)" onclick='toggle_search()'>Search</a> +</ul> +</div> +<div class="menu submenu" id="submenu"> +<ul> +<li><a href='../about.html'>About</a> +<li><a href='../docs.html'>Documentation</a> +<li><a href='../download.html'>Download</a> +<li><a href='../support.html'>Support</a> +<li><a href='../prosupport.html'>Purchase</a> +</ul> +</div> +<div class="searchmenu" id="searchmenu"> +<form method="GET" action="../search"> +<select name="s" id="searchtype"> +<option value="d">Search Documentation</option> +<option value="c">Search Changelog</option> +</select> +<input type="text" name="q" id="searchbox" value=""> +<input type="submit" value="Go"> +</form> +</div> +</div> +<script> +function toggle_div(nm) { +var w = document.getElementById(nm); +if( w.style.display=="block" ){ +w.style.display = "none"; +}else{ +w.style.display = "block"; +} +} +function toggle_search() { +var w = document.getElementById("searchmenu"); +if( w.style.display=="block" ){ +w.style.display = "none"; +} else { +w.style.display = "block"; +setTimeout(function(){ +document.getElementById("searchbox").focus() +}, 30); +} +} +function div_off(nm){document.getElementById(nm).style.display="none";} +window.onbeforeunload = function(e){div_off("submenu");} +/* Disable the Search feature if we are not operating from CGI, since */ +/* Search is accomplished using CGI and will not work without it. */ +if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){ +document.getElementById("search_menubutton").style.display = "none"; +} +/* Used by the Hide/Show button beside syntax diagrams, to toggle the */ +function hideorshow(btn,obj){ +var x = document.getElementById(obj); +var b = document.getElementById(btn); +if( x.style.display!='none' ){ +x.style.display = 'none'; +b.innerHTML='show'; +}else{ +x.style.display = ''; +b.innerHTML='hide'; +} +return false; +} +var antiRobot = 0; +function antiRobotGo(){ +if( antiRobot!=3 ) return; +antiRobot = 7; +var j = document.getElementById("mtimelink"); +if(j && j.hasAttribute("data-href")) j.href=j.getAttribute("data-href"); +} +function antiRobotDefense(){ +document.body.onmousedown=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousedown=null; +} +document.body.onmousemove=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousemove=null; +} +setTimeout(function(){ +antiRobot |= 1; +antiRobotGo(); +}, 100) +antiRobotGo(); +} +antiRobotDefense(); +</script> +<!-- keywords: snapshot sqlite3_snapshot --> +<div class=nosearch> +<a href="../c3ref/intro.html"><h2>SQLite C Interface</h2></a> +<h2>Database Snapshot</h2> +</div> +<blockquote><pre> +typedef struct sqlite3_snapshot { + unsigned char hidden[48]; +} sqlite3_snapshot; +</pre></blockquote> +<p> +An instance of the snapshot object records the state of a <a href="../wal.html">WAL mode</a> +database for some specific point in history.</p> + +<p>In <a href="../wal.html">WAL mode</a>, multiple <a href="../c3ref/sqlite3.html">database connections</a> that are open on the +same database file can each be reading a different historical version +of the database file. When a <a href="../c3ref/sqlite3.html">database connection</a> begins a read +transaction, that connection sees an unchanging copy of the database +as it existed for the point in time when the transaction first started. +Subsequent changes to the database from other connections are not seen +by the reader until a new read transaction is started.</p> + +<p>The sqlite3_snapshot object records state information about an historical +version of the database file so that it is possible to later open a new read +transaction that sees that historical version of the database rather than +the most recent version. +</p><p>1 Constructor using this object: <a href="../c3ref/snapshot_get.html">sqlite3_snapshot_get()</a></p> +<p>1 Destructor using this object: <a href="../c3ref/snapshot_free.html">sqlite3_snapshot_free()</a></p> +<p>3 Methods using this object: + <a href="../c3ref/snapshot_cmp.html">sqlite3_snapshot_cmp()</a>, +<a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open()</a>, +<a href="../c3ref/snapshot_recover.html">sqlite3_snapshot_recover()</a></p> +<p>See also lists of + <a href="../c3ref/objlist.html">Objects</a>, + <a href="../c3ref/constlist.html">Constants</a>, and + <a href="../c3ref/funclist.html">Functions</a>.</p> + |