greptimedb/partition/function/index.html

<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="`iceberg_hash`, the hash allowed on the column side of a partition rule."><title>partition::function - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-1ed95124.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="partition" data-themes="" data-resource-suffix="" data-rustdoc-version="1.98.1 (48a229cea 2026-09-01)" data-channel="1.98.1" data-search-js="search-9944d736.js" data-stringdex-js="stringdex-2da4960a.js" data-settings-js="settings-170eb4bf.js" ><script src="../../static.files/storage-41dd4d93.js"></script><script defer src="../sidebar-items.js"></script><script defer src="../../static.files/main-417ebf0a.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-f7c3ffd8.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc mod"><a class="skip-main-content" href="#main-content">Skip to main content</a><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">Module function</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../partition/index.html">partition</a><span class="version">1.4.0-alpha.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Module function</a></h2><h3><a href="#structs">Module Items</a></h3><ul class="block"><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#functions" title="Functions">Functions</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="../index.html">In crate partition</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content" tabindex="-1"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../index.html">partition</a></div><h1>Module <span>function</span>&nbsp;<button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../src/partition/function.rs.html#15-345">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p><code>iceberg_hash</code>, the hash allowed on the column side of a partition rule.</p>
<p>The hash decides which region a row is written to and is persisted in
partition metadata, so its result for a given input must never change across
versions. A different algorithm needs a new type.</p>
<p>Rule simplification and coverage checks treat the hash as an independent
dimension, which holds because it is defined for every value of the accepted
column types.</p>
</div></details><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><dl class="item-table"><dt><a class="struct" href="struct.IcebergHash.html" title="struct partition::function::IcebergHash">Iceberg<wbr>Hash</a></dt><dd><code>iceberg_hash(column)</code>: the 32-bit Murmur3 hash defined by the Iceberg table
spec (appendix B) over a string or integer column, as an <code>INT</code>.</dd><dt><a class="struct" href="struct.IcebergHashUdf.html" title="struct partition::function::IcebergHashUdf">Iceberg<wbr>Hash<wbr>Udf</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>DataFusion form of <a href="struct.IcebergHash.html" title="struct partition::function::IcebergHash"><code>IcebergHash</code></a>, so storage engines
can evaluate a region’s partition expression as a filter.</dd></dl><h2 id="functions" class="section-header">Functions<a href="#functions" class="anchor">§</a></h2><dl class="item-table"><dt><a class="fn" href="fn.hash_long.html" title="fn partition::function::hash_long">hash_<wbr>long</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.iceberg_hash_array.html" title="fn partition::function::iceberg_hash_array">iceberg_<wbr>hash_<wbr>array</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.is_signed_integer.html" title="fn partition::function::is_signed_integer">is_<wbr>signed_<wbr>integer</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.murmur3_32.html" title="fn partition::function::murmur3_32">murmur3_<wbr>32</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>MurmurHash3 x86 32-bit with seed 0, returned as a signed integer like Iceberg.</dd></dl></section></div></main></body></html>