1 files changed, 173 insertions, 0 deletions
diff --git a/www/c3ref/snapshot_open.html b/www/c3ref/snapshot_open.html
new file mode 100644
index 0000000..e1377dd
--- /dev/null
+++ b/www/c3ref/snapshot_open.html
@@ -0,0 +1,173 @@
+<!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>Start a read transaction on an historical 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: sqlite3_snapshot_open -->
+<div class=nosearch>
+<a href="intro.html"><h2>SQLite C Interface</h2></a>
+<h2>Start a read transaction on an historical snapshot</h2>
+</div>
+<blockquote><pre>
+int sqlite3_snapshot_open(
+  sqlite3 *db,
+  const char *zSchema,
+  sqlite3_snapshot *pSnapshot
+);
+</pre></blockquote>
+<p>
+The <a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open(D,S,P)</a> interface either starts a new read
+transaction or upgrades an existing one for schema S of
+<a href="../c3ref/sqlite3.html">database connection</a> D such that the read transaction refers to
+historical <a href="../c3ref/snapshot.html">snapshot</a> P, rather than the most recent change to the
+database. The <a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open()</a> interface returns SQLITE_OK
+on success or an appropriate <a href="../rescode.html">error code</a> if it fails.</p>
+
+<p>In order to succeed, the database connection must not be in
+<a href="../c3ref/get_autocommit.html">autocommit mode</a> when <a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open(D,S,P)</a> is called. If there
+is already a read transaction open on schema S, then the database handle
+must have no active statements (SELECT statements that have been passed
+to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
+SQLITE_ERROR is returned if either of these conditions is violated, or
+if schema S does not exist, or if the snapshot object is invalid.</p>
+
+<p>A call to sqlite3_snapshot_open() will fail to open if the specified
+snapshot has been overwritten by a <a href="../wal.html#ckpt">checkpoint</a>. In this case
+SQLITE_ERROR_SNAPSHOT is returned.</p>
+
+<p>If there is already a read transaction open when this function is
+invoked, then the same read transaction remains open (on the same
+database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
+is returned. If another error code - for example SQLITE_PROTOCOL or an
+SQLITE_IOERR error code - is returned, then the final state of the
+read transaction is undefined. If SQLITE_OK is returned, then the
+read transaction is now open on database snapshot P.</p>
+
+<p>A call to <a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open(D,S,P)</a> will fail if the
+database connection D does not know that the database file for
+schema S is in <a href="../wal.html">WAL mode</a>.  A database connection might not know
+that the database file is in <a href="../wal.html">WAL mode</a> if there has been no prior
+I/O on that database connection, or if the database entered <a href="../wal.html">WAL mode</a>
+after the most recent I/O on the database connection.
+(Hint: Run "<a href="../pragma.html#pragma_application_id">PRAGMA application_id</a>" against a newly opened
+database connection in order to make it ready to use snapshots.)</p>
+
+<p>The <a href="../c3ref/snapshot_open.html">sqlite3_snapshot_open()</a> interface is only available when the
+<a href="../compile.html#enable_snapshot">SQLITE_ENABLE_SNAPSHOT</a> compile-time option is used.
+</p><p>See also lists of
+  <a href="objlist.html">Objects</a>,
+  <a href="constlist.html">Constants</a>, and
+  <a href="funclist.html">Functions</a>.</p>
+