greptimedb/query/dist_plan/merge_scan/fn.fields_semantically_equal.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="Returns true when two fields describe the same column semantics: same name, same data type, and compatible nullability."><title>fields_semantically_equal in query::dist_plan::merge_scan - 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="query" 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 fn"><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="#">fields_semantically_equal</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../../query/index.html">query</a><span class="version">1.4.0-alpha.0</span></h2></div><div class="sidebar-elems"><div id="rustdoc-modnav"><h2><a href="index.html">In query::<wbr>dist_<wbr>plan::<wbr>merge_<wbr>scan</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">query</a>::<wbr><a href="../index.html">dist_plan</a>::<wbr><a href="index.html">merge_scan</a></div><h1>Function <span class="fn">fields_<wbr>semantically_<wbr>equal</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/query/dist_plan/merge_scan.rs.html#191-195">Source</a> </span></div><pre class="rust item-decl"><code>fn fields_semantically_equal(
    expected_field: &amp;Field,
    actual_field: &amp;Field,
) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.98.1/std/primitive.bool.html">bool</a></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Returns true when two fields describe the same column semantics: same
name, same data type, and compatible nullability.</p>
<p>Arrow <code>Field</code> metadata is auxiliary information (indexing, encoding,
compression hints, …) and does not participate in the comparison. This
applies to every field, JSON columns included: JSON identity keys
(<code>greptime:type</code>, <code>ARROW:extension:metadata</code>) are never compared here.
The wire/decoded physical-type difference of JSON columns is exempted
separately by <a href="fn.json_fields_compatible.html" title="fn query::dist_plan::merge_scan::json_fields_compatible"><code>json_fields_compatible</code></a>.</p>
</div></details></section></div></main></body></html>