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diff --git a/www/formatchng.html b/www/formatchng.html new file mode 100644 index 0000000..3d3c76f --- /dev/null +++ b/www/formatchng.html @@ -0,0 +1,166 @@ +<!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>File Format Changes in SQLite</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> + + +<h2>File Format Changes in SQLite</h2> + +<p> +The <a href="fileformat2.html">underlying file format</a> for SQLite databases does not +change in incompatible ways. There are literally trillions of +SQLite database files in circulation and the SQLite developers are +committing to supporting those files for decades into the future. +</p> + +<p> +Prior to SQLite version 3.0.0 (2004-06-18), the file format did +sometimes change from one release to the next. But since that time, +the file format has been fully backwards compatible. +</p> + +<p> +By "backwards compatible" we mean that +newer versions of SQLite can always read and write database files created +by older versions of SQLite. +It is often also the case that SQLite is "forwards compatible", that +older versions of SQLite can read and write database files created by +newer versions of SQLite. But there are sometimes forward compatibility +breaks. Sometimes new features are added to the file format. For +example, <a href="wal.html">WAL mode</a> was added in version 3.7.0 (2010-07-21). +SQLite 3.7.0 and later can read and write all database files created +by earlier versions of SQLite. And earlier versions of SQLite can +read and write database files created by SQLite 3.7.0 and later +<i>as long as the database does not use WAL mode</i>. But versions of +SQLite prior to version 3.7.0 cannot read nor write SQLite database files +that make use of WAL mode. +</p> + +<h2>Summary</h2> + +<ul> +<li><p> +Newer versions of SQLite can always read and/or write database files +created by older versions of SQLite, back to version 3.0.0 (2004-06-18). + +<li><p> +Older versions of SQLite back to version 3.0.0 can read and write +database files created by newer versions of SQLite as long as the +database does not make use of newer features that are unknown to that +older version. +</ul> +<p align="center"><small><i>This page last modified on <a href="https://sqlite.org/docsrc/honeypot" id="mtimelink" data-href="https://sqlite.org/docsrc/finfo/pages/formatchng.in?m=8415958e0a">2022-09-13 14:04:46</a> UTC </small></i></p> + |