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diff --git a/www/footprint.html b/www/footprint.html new file mode 100644 index 0000000..e06a88b --- /dev/null +++ b/www/footprint.html @@ -0,0 +1,220 @@ +<!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>SQLite Library Footprint</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> + + + + +<h1 align="center">Size Of The SQLite Library</h1> + +<p> +The code space used by the SQLite library depends on the target +platform, the compiler, and optimization settings. These variables +also affect performance. +</p> + +<p> +The chart below shows the relative size and performance for SQLite +as of 2017-10-08 for various compilers and optimization settings +as tested on Ubuntu 16.04.3 on x86_64. General observations: + +<ol> +<li><p> +The Clang/LLVM compiler is not competitive with GCC. Clang-generated +binaries are consistently larger and slower than GCC-generated binaries. + +<li><p> +Profile guided optimization (PGO) is not helpful with SQLite. PGO results +in binaries that are about 1% larger and about 0.33% slower. + +<li><p> +GCC-7 generates binaries that are smaller and faster than GCC-5, though +the difference is not that great. + +<li><p> +Compiling with GCC and -Os results in a binary that is slightly less +than 500KB in size. (Update 2018-07-07: Due to the addition of new +features such as <a href="lang_upsert.html">UPSERT</a> and <a href="windowfunctions.html">window functions</a>, the library footprint +is now slightly larger than 500KB.) + +<li><p> +The only significant design decision that developers need to make is +whether to use -Os (optimize for size) or -O6 (optimize for speed). +The -O6 setting makes binaries that run about 2% or 3% faster, but which +are also 66% larger. The performance here is measured by counting CPU +cycles using cachegrind. I-cache misses are not considered in the +analysis. If I-cache misses are considered, builds with -O6 might not +be any faster than builds with -Os. + +<li><p> +Taking into consideration all of the above, the SQLite developers recommend +compiling SQLite using GCC-7 with the -Os optimization setting. +</ol> + +<hr> +<center> +<img src='images/cc-diff.jpg'> +</center> +</hr> + +<h1>Details</h1> + +<ul> +<li><p> +Measurements above were conducted using SQLite version +<a href="https://sqlite.org/src/timeline?c=5594a121bf132a98">5594a121bf132a98</a> from +2017-10-08. + +<li><p> +The only SQLite compile-time option used was <a href="compile.html#enable_memsys5">-DSQLITE_ENABLE_MEMSYS5</a>. +The optional <a href="malloc.html#memsys5">memsys5</a> memory allocator is used for performance testing +because it gives results that are more repeatable than the library-supplied +malloc()/free() on Ubuntu. + +<li><p> +Performance can be improved and the size reduced by +enabling <a href="compile.html#threadsafe">-DSQLITE_THREADSAFE=0</a>, +<a href="compile.html#default_memstatus">-DSQLITE_DEFAULT_MEMSTATUS=0</a>, +<a href="compile.html#default_wal_synchronous">-DSQLITE_DEFAULT_WAL_SYNCHRONOUS=1</a>, +<a href="compile.html#like_doesnt_match_blobs">-DSQLITE_LIKE_DOESNT_MATCH_BLOBS</a>, +<a href="limits.html#max_expr_depth">-DSQLITE_MAX_EXPR_DEPTH=0</a>, +<a href="compile.html#omit_decltype">-DSQLITE_OMIT_DECLTYPE</a>, +<a href="compile.html#omit_deprecated">-DSQLITE_OMIT_DEPRECATED</a>, +<a href="compile.html#omit_progress_callback">-DSQLITE_OMIT_PROGRESS_CALLBACK</a>, +<a href="compile.html#omit_shared_cache">-DSQLITE_OMIT_SHARED_CACHE</a>, and +<a href="compile.html#use_alloca">-DSQLITE_USE_ALLOCA</a>. +All these options together result in about a 3.5% performance increase and +a 3.0% size reduction. + +<li><p> +Adding optional features like <a href="compile.html#enable_json1">-DSQLITE_ENABLE_JSON1</a>, +<a href="compile.html#enable_fts5">-DSQLITE_ENABLE_FTS5</a>, or <a href="compile.html#enable_rtree">-DSQLITE_ENABLE_RTREE</a> will increase the +size of the library, obviously. + +<li><p> +Performance was measured using the +<a href="https://sqlite.org/src/file/test/speedtest1.c">speedtest1.c</a> utility program, +which attempts to mimic a typical workload for SQLite. Options to +the test runs are: +<blockquote> +<tt>--shrink-memory --reprepare --stats --heap 10000000 64 --size 5</tt> +</blockquote> +Performance was measured by running speedtest1 using cachegrind and +observing the "I refs" output. +</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/footprint.in?m=47a6a3e3fe406f4a1">2018-07-07 17:44:20</a> UTC </small></i></p> + |