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</a> <ul id="toc-Use-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-PHTree" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#PHTree"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>PHTree</span> </div> </a> <ul id="toc-PHTree-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>External links</span> </div> </a> <ul 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class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Tree data structure for directory indexing</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Not to be confused with <a href="/wiki/H_tree" title="H tree">H tree</a>, a family of fractal sets.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Primary_sources plainlinks metadata ambox ambox-content ambox-Primary_sources" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>relies excessively on <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">references</a> to <a href="/wiki/Wikipedia:No_original_research#Primary,_secondary_and_tertiary_sources" title="Wikipedia:No original research">primary sources</a></b>.<span class="hide-when-compact"> Please improve this article by adding <a href="/wiki/Wikipedia:No_original_research#Primary,_secondary_and_tertiary_sources" title="Wikipedia:No original research">secondary or tertiary sources</a>. <br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22HTree%22">"HTree"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22HTree%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22HTree%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22HTree%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22HTree%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22HTree%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">September 2013</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>An <b>HTree</b> is a specialized <a href="/wiki/Tree_(data_structure)" class="mw-redirect" title="Tree (data structure)">tree data structure</a> for directory indexing, similar to a <a href="/wiki/B-tree" title="B-tree">B-tree</a>. They are constant depth of either one or two levels, have a high fanout factor, use a <a href="/wiki/Hash_table" title="Hash table">hash</a> of the <a href="/wiki/Filename" title="Filename">filename</a>, and do not require <a href="/wiki/Balanced_tree" class="mw-redirect" title="Balanced tree">balancing</a>.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The HTree algorithm is distinguished from standard B-tree methods by its treatment of <a href="/wiki/Hash_collision" title="Hash collision">hash collisions</a>, which may overflow across multiple leaf and index blocks. HTree <a href="/wiki/Index_(database)" class="mw-redirect" title="Index (database)">indexes</a> are used in the <a href="/wiki/Ext3" title="Ext3">ext3</a> and <a href="/wiki/Ext4" title="Ext4">ext4</a> <a href="/wiki/Linux" title="Linux">Linux</a> <a href="/wiki/Filesystem" class="mw-redirect" title="Filesystem">filesystems</a>, and were incorporated into the <a href="/wiki/Linux_kernel" title="Linux kernel">Linux kernel</a> around 2.5.40.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> HTree indexing improved the scalability of <a href="/wiki/Linux" title="Linux">Linux</a> ext2 based filesystems from a practical limit of a few thousand files, into the range of tens of millions of files per directory. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=HTree&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The HTree index data structure and algorithm were developed by Daniel Phillips in 2000 and implemented for the ext2 filesystem in February 2001. A port to the ext3 filesystem by Christopher Li and <a href="/wiki/Andrew_Morton_(computer_programmer)" title="Andrew Morton (computer programmer)">Andrew Morton</a> in 2002 during the 2.5 <a href="/wiki/Kernel_(operating_system)" title="Kernel (operating system)">kernel</a> series added <a href="/wiki/Journaling_file_system" title="Journaling file system">journal</a> based crash consistency. With minor improvements, HTree continues to be used in ext4 in the Linux 3.x.x kernel series. </p> <div class="mw-heading mw-heading2"><h2 id="Use">Use</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=HTree&action=edit&section=2" title="Edit section: Use"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Ext2" title="Ext2">ext2</a> HTree indexes were originally developed for ext2 but the patch never made it to the official branch. The dir_index feature can be enabled when creating an ext2 filesystem, but the ext2 code won't act on it.</li> <li><a href="/wiki/Ext3" title="Ext3">ext3</a> HTree indexes are available in ext3 when the dir_index feature is enabled.</li> <li><a href="/wiki/Ext4" title="Ext4">ext4</a> HTree indexes are turned on by default in ext4. This feature is implemented in Linux kernel 2.6.23. HTree indexes is also used for file <a href="/wiki/Extent_(file_systems)" title="Extent (file systems)">extents</a> when a file needs more than the 4 extents stored in the <a href="/wiki/Inode" title="Inode">inode</a>. The large_dir feature of ext4 is implemented in Linux kernel 4.13.</li></ul> <div class="mw-heading mw-heading2"><h2 id="PHTree">PHTree</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=HTree&action=edit&section=3" title="Edit section: PHTree"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>PHTree (Physically stable HTree) is a derivation intended as a successor.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Reliable_sources" title="Wikipedia:Reliable sources"><span title="The material near this tag may rely on an unreliable source. (December 2014)">unreliable source?</span></a></i>]</sup> It fixes all the known issues with HTree except for write multiplication.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (December 2014)">citation needed</span></a></i>]</sup> It is used in the <a href="/wiki/Tux3" title="Tux3">Tux3</a> filesystem.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=HTree&action=edit&section=4" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output 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.mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFMingming_Cao" class="citation web cs1">Mingming Cao. <a rel="nofollow" class="external text" href="https://www.kernel.org/doc/ols/2005/ols2005v1-pages-77-104.pdf">"Directory indexing"</a> <span class="cs1-format">(PDF)</span>. <i>Features found in Linux 2.6</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Features+found+in+Linux+2.6&rft.atitle=Directory+indexing&rft.au=Mingming+Cao&rft_id=https%3A%2F%2Fwww.kernel.org%2Fdoc%2Fols%2F2005%2Fols2005v1-pages-77-104.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHTree" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFtytso@mit.edu" class="citation web cs1">tytso@mit.edu. <a rel="nofollow" class="external text" href="https://lwn.net/Articles/11481/">"Add ext3 indexed directory (htree) support"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Add+ext3+indexed+directory+%28htree%29+support&rft.au=tytso%40mit.edu&rft_id=https%3A%2F%2Flwn.net%2FArticles%2F11481%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHTree" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://phunq.net/pipermail/tux3/2013-January/000026.html">"PHTree design refresh"</a>. 4 January 2013.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=PHTree+design+refresh&rft.date=2013-01-04&rft_id=http%3A%2F%2Fphunq.net%2Fpipermail%2Ftux3%2F2013-January%2F000026.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHTree" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150113101112/http://tux3.org/design.html">"Tux3 Versioning Filesystem"</a>. Archived from <a rel="nofollow" class="external text" href="http://tux3.org/design.html">the original</a> on 13 January 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">28 December</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Tux3+Versioning+Filesystem&rft_id=http%3A%2F%2Ftux3.org%2Fdesign.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHTree" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=HTree&action=edit&section=5" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://archive.today/20130415075208/http://www.linuxshowcase.org/2001/full_papers/phillips/phillips_html/index.html">A Directory Index for Ext2 (which describes the HTree data structure)</a></li> <li><a rel="nofollow" class="external text" href="https://www.kernel.org/doc/ols/2005/ols2005v1-pages-77-104.pdf">HTree</a></li> <li><a rel="nofollow" class="external text" href="https://wiki.hpdd.intel.com/display/PUB/Parallel+Directory+High+Level+Design">HPDD Wiki - Parallel Directory High Level Design</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul 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.navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Tree_data_structures237" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:CS_trees" title="Template:CS trees"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:CS_trees" title="Template talk:CS trees"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:CS_trees" title="Special:EditPage/Template:CS trees"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Tree_data_structures237" style="font-size:114%;margin:0 4em"><a href="/wiki/Tree_(abstract_data_type)" title="Tree (abstract data type)">Tree data structures</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Search_tree" title="Search tree">Search trees</a><br />(<a href="/wiki/Set_(abstract_data_type)" title="Set (abstract data type)">dynamic sets</a>/<a href="/wiki/Associative_array" title="Associative array">associative arrays</a>)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/2%E2%80%933_tree" title="2–3 tree">2–3</a></li> <li><a href="/wiki/2%E2%80%933%E2%80%934_tree" title="2–3–4 tree">2–3–4</a></li> <li><a href="/wiki/AA_tree" title="AA tree">AA</a></li> <li><a href="/wiki/(a,b)-tree" class="mw-redirect" title="(a,b)-tree">(a,b)</a></li> <li><a href="/wiki/AVL_tree" title="AVL tree">AVL</a></li> <li><a href="/wiki/B-tree" title="B-tree">B</a></li> <li><a href="/wiki/B%2B_tree" title="B+ tree">B+</a></li> <li><a href="/wiki/B*-tree" class="mw-redirect" title="B*-tree">B*</a></li> <li><a href="/wiki/Bx-tree" title="Bx-tree">B<sup>x</sup></a></li> <li>(<a href="/wiki/Optimal_binary_search_tree" title="Optimal binary search tree">Optimal</a>) <a href="/wiki/Binary_search_tree" title="Binary search tree">Binary search</a></li> <li><a href="/wiki/Dancing_tree" title="Dancing tree">Dancing</a></li> <li><a class="mw-selflink selflink">HTree</a></li> <li><a href="/wiki/Interval_tree" title="Interval tree">Interval</a></li> <li><a href="/wiki/Order_statistic_tree" title="Order statistic tree">Order statistic</a></li> <li><a href="/wiki/Palindrome_tree" title="Palindrome tree">Palindrome</a></li> <li>(<a href="/wiki/Left-leaning_red%E2%80%93black_tree" title="Left-leaning red–black tree">Left-leaning</a>) <a href="/wiki/Red%E2%80%93black_tree" title="Red–black tree">Red–black</a></li> <li><a href="/wiki/Scapegoat_tree" title="Scapegoat tree">Scapegoat</a></li> <li><a href="/wiki/Splay_tree" title="Splay tree">Splay</a></li> <li><a href="/wiki/T-tree" title="T-tree">T</a></li> <li><a href="/wiki/Treap" title="Treap">Treap</a></li> <li><a href="/wiki/UB-tree" title="UB-tree">UB</a></li> <li><a href="/wiki/Weight-balanced_tree" title="Weight-balanced tree">Weight-balanced</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Heap_(data_structure)" title="Heap (data structure)">Heaps</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Binary_heap" title="Binary heap">Binary</a></li> <li><a href="/wiki/Binomial_heap" title="Binomial heap">Binomial</a></li> <li><a href="/wiki/Brodal_queue" title="Brodal queue">Brodal</a></li> <li><a href="/wiki/D-ary_heap" title="D-ary heap"><i>d</i>-ary</a></li> <li><a href="/wiki/Fibonacci_heap" title="Fibonacci heap">Fibonacci</a></li> <li><a href="/wiki/Leftist_tree" title="Leftist tree">Leftist</a></li> <li><a href="/wiki/Pairing_heap" title="Pairing heap">Pairing</a></li> <li><a href="/wiki/Skew_binomial_heap" title="Skew binomial heap">Skew binomial</a></li> <li><a href="/wiki/Skew_heap" title="Skew heap">Skew</a></li> <li><a href="/wiki/Van_Emde_Boas_tree" title="Van Emde Boas tree">van Emde Boas</a></li> <li><a href="/wiki/Weak_heap" title="Weak heap">Weak</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Trie" title="Trie">Tries</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ctrie" title="Ctrie">Ctrie</a></li> <li><a href="/wiki/C-trie" title="C-trie">C-trie (compressed ADT)</a></li> <li><a href="/wiki/Hash_tree_(persistent_data_structure)" title="Hash tree (persistent data structure)">Hash</a></li> <li><a href="/wiki/Radix_tree" title="Radix tree">Radix</a></li> <li><a href="/wiki/Suffix_tree" title="Suffix tree">Suffix</a></li> <li><a href="/wiki/Ternary_search_tree" title="Ternary search tree">Ternary search</a></li> <li><a href="/wiki/X-fast_trie" title="X-fast trie">X-fast</a></li> <li><a href="/wiki/Y-fast_trie" title="Y-fast trie">Y-fast</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Spatial_index" class="mw-redirect" title="Spatial index">Spatial</a> data partitioning trees</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ball_tree" title="Ball tree">Ball</a></li> <li><a href="/wiki/BK-tree" title="BK-tree">BK</a></li> <li><a href="/wiki/BSP_tree" class="mw-redirect" title="BSP tree">BSP</a></li> <li><a href="/wiki/Cartesian_tree" title="Cartesian tree">Cartesian</a></li> <li><a href="/wiki/Hilbert_R-tree" title="Hilbert R-tree">Hilbert R</a></li> <li><a href="/wiki/K-d_tree" title="K-d tree"><i>k</i>-d</a> (<a href="/wiki/Implicit_k-d_tree" title="Implicit k-d tree">implicit <i>k</i>-d</a>)</li> <li><a href="/wiki/M-tree" title="M-tree">M</a></li> <li><a href="/wiki/Metric_tree" title="Metric tree">Metric</a></li> <li><a href="/wiki/MVP_tree" class="mw-redirect" title="MVP tree">MVP</a></li> <li><a href="/wiki/Octree" title="Octree">Octree</a></li> <li><a href="/wiki/PH-tree" title="PH-tree">PH</a></li> <li><a href="/wiki/Priority_R-tree" title="Priority R-tree">Priority R</a></li> <li><a href="/wiki/Quadtree" title="Quadtree">Quad</a></li> <li><a href="/wiki/R-tree" title="R-tree">R</a></li> <li><a href="/wiki/R%2B_tree" title="R+ tree">R+</a></li> <li><a href="/wiki/R*_tree" class="mw-redirect" title="R* tree">R*</a></li> <li><a href="/wiki/Segment_tree" title="Segment tree">Segment</a></li> <li><a href="/wiki/Vantage-point_tree" title="Vantage-point tree">VP</a></li> <li><a href="/wiki/X-tree" title="X-tree">X</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other trees</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cover_tree" title="Cover tree">Cover</a></li> <li><a href="/wiki/Exponential_tree" title="Exponential tree">Exponential</a></li> <li><a href="/wiki/Fenwick_tree" title="Fenwick tree">Fenwick</a></li> <li><a href="/wiki/Finger_tree" title="Finger tree">Finger</a></li> <li><a href="/wiki/Fractal_tree_index" title="Fractal tree index">Fractal tree index</a></li> <li><a href="/wiki/Fusion_tree" title="Fusion tree">Fusion</a></li> <li><a href="/wiki/Hash_calendar" title="Hash calendar">Hash calendar</a></li> <li><a href="/wiki/IDistance" title="IDistance">iDistance</a></li> <li><a href="/wiki/K-ary_tree" class="mw-redirect" title="K-ary tree">K-ary</a></li> <li><a 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