greptimedb/catalog/system_schema/semantic_graph/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="The computed entity-graph tables `greptime_private.semantic_entities` and `greptime_private.semantic_relationships`."><title>catalog::system_schema::semantic_graph - 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="catalog" 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 semantic_graph</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../../catalog/index.html">catalog</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 semantic_<wbr>graph</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="#enums" title="Enums">Enums</a></li><li><a href="#statics" title="Statics">Statics</a></li><li><a href="#traits" title="Traits">Traits</a></li><li><a href="#functions" title="Functions">Functions</a></li><li><a href="#types" title="Type Aliases">Type Aliases</a></li></ul></section><div id="rustdoc-modnav"><h2><a href="../index.html">In catalog::<wbr>system_<wbr>schema</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">catalog</a>::<wbr><a href="../index.html">system_schema</a></div><h1>Module <span>semantic_<wbr>graph</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/catalog/system_schema/semantic_graph.rs.html#15-479">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>The computed entity-graph tables <code>greptime_private.semantic_entities</code> and
<code>greptime_private.semantic_relationships</code>.</p>
<p>They live in <code>greptime_private</code>, not <code>information_schema</code>: scanning them
triggers read-time derivation over telemetry tables (trace self-joins, …),
which breaks the “cheap, metadata-only” expectation users have of
<code>information_schema</code>. <code>greptime_private</code> also hosts the physical
declared-edge table (<code>semantic_relationships_declared</code>), whose rows are
unioned into the computed <code>semantic_relationships</code>.</p>
<p>These are thin forwarders: their rows are derived at read time by the injected
<a href="trait.EntityGraphProvider.html" title="trait catalog::system_schema::semantic_graph::EntityGraphProvider"><code>EntityGraphProvider</code></a>, which enumerates the <code>table_semantics</code> declarations,
builds typed DataFusion derivation plans, and executes them via the query
engine. When no provider is injected (e.g. before the engine is up, or on a
non-frontend node) they stream empty. The fixed schemas here must match the
columns the provider’s plans project; JSON columns are <code>json</code> (JSONB), whose
Arrow storage type is <code>Binary</code> — the derived batches are rebuilt against the
declared Arrow schema (which carries the <code>json</code> extension metadata) in
<a href="../trait.SystemTable.html#tymethod.to_stream" title="method catalog::system_schema::SystemTable::to_stream"><code>SystemTable::to_stream</code></a>.</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.SemanticGraphTable.html" title="struct catalog::system_schema::semantic_graph::SemanticGraphTable">Semantic<wbr>Graph<wbr>Table</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Forwarder for a computed entity-graph table.</dd><dt><a class="struct" href="struct.SemanticGraphTableProvider.html" title="struct catalog::system_schema::semantic_graph::SemanticGraphTableProvider">Semantic<wbr>Graph<wbr>Table<wbr>Provider</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Serves the computed graph tables under <code>greptime_private</code>, overlaid on the
schema’s physical tables the same way the <code>numbers</code> table overlays <code>public</code>
(the system catalog is consulted before physical table resolution).</dd><dt><a class="struct" href="struct.TableEntityDeclaration.html" title="struct catalog::system_schema::semantic_graph::TableEntityDeclaration">Table<wbr>Entity<wbr>Declaration</a></dt><dd>One entity a table declares, as <code>information_schema.table_semantics</code>
reports it. A catalog-side projection of the derivation’s own declaration
type, which lives above this crate.</dd></dl><h2 id="enums" class="section-header">Enums<a href="#enums" class="anchor">§</a></h2><dl class="item-table"><dt><a class="enum" href="enum.DeclarationOrigin.html" title="enum catalog::system_schema::semantic_graph::DeclarationOrigin">Declaration<wbr>Origin</a></dt><dd>Where a table’s entity declaration came from.</dd><dt><a class="enum" href="enum.GraphTableKind.html" title="enum catalog::system_schema::semantic_graph::GraphTableKind">Graph<wbr>Table<wbr>Kind</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Which computed table this shell represents, so the two share one forwarder.</dd></dl><h2 id="statics" class="section-header">Statics<a href="#statics" class="anchor">§</a></h2><dl class="item-table"><dt><a class="static" href="static.ENTITIES_SCHEMA.html" title="static catalog::system_schema::semantic_graph::ENTITIES_SCHEMA">ENTITIES_<wbr>SCHEMA</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Schema of <code>semantic_entities</code> — the node set of the graph, one row per entity
observed in a time window. Must match the registry derivation projection.</dd><dt><a class="static" href="static.RELATIONSHIPS_SCHEMA.html" title="static catalog::system_schema::semantic_graph::RELATIONSHIPS_SCHEMA">RELATIONSHIPS_<wbr>SCHEMA</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Schema of <code>semantic_relationships</code> — the edge set of the graph, one row per
edge observed in a time window. This is the 18-column contract every derived
branch and the declared-edge table must project for the top-level <code>UNION ALL</code>.</dd></dl><h2 id="traits" class="section-header">Traits<a href="#traits" class="anchor">§</a></h2><dl class="item-table"><dt><a class="trait" href="trait.EntityGraphProvider.html" title="trait catalog::system_schema::semantic_graph::EntityGraphProvider">Entity<wbr>Graph<wbr>Provider</a></dt><dd>Produces the rows of the computed entity-graph tables at read time.</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.json.html" title="fn catalog::system_schema::semantic_graph::json">json</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.string.html" title="fn catalog::system_schema::semantic_graph::string">string</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.ts.html" title="fn catalog::system_schema::semantic_graph::ts">ts</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt></dl><h2 id="types" class="section-header">Type Aliases<a href="#types" class="anchor">§</a></h2><dl class="item-table"><dt><a class="type" href="type.EntityGraphProviderRef.html" title="type catalog::system_schema::semantic_graph::EntityGraphProviderRef">Entity<wbr>Graph<wbr>Provider<wbr>Ref</a></dt></dl></section></div></main></body></html>