/query

Write a mesh query that is anchored, projected and readable as evidence — the mandatory select:, why an unanchored query is refused rather than answered, why a namespace alternation silently drops Admin, how to read count against coverage.partitions, and how to retrieve a schema to learn property names.

• Instructions: The full query **language** — every field filter, wildcard, scope, sort and qualifier — is the `meshweaver://reference/tools` MCP resource, under *Full Query Syntax Reference*. Read it for syntax. This skill is what that reference does not tell you: the rules that decide whether a query is **cheap, correct, and readable as evidence**, and what each one costs when it is missed. ## 1. 🚨 ALWAYS project — `select:` is mandatory **Every query names the fields it needs.** Without `select:` a query returns whole nodes, **content included** — every markdown body, every activity log, every document — in order to display a path and a name. ```text ✅ namespace:{user}/_Notification nodeType:Notification sort:CreatedAt-desc select:path,name,nodeType,icon,lastModified ❌ namespace:{user}/_Notification nodeType:Notification sort:CreatedAt-desc ``` The cost is invisible on a test mesh of ten small nodes and ruinous on a real one, and it is paid on **every** render for **every** viewer. Name the columns you will actually display. ## 2. 🚨 ALWAYS anchor — an unanchored query is REFUSED, not answered A query must say WHERE to look: `namespace:X`, `path:X`, the `basePath` argument, or an explicit `partitions:all`. One that does neither comes back as `{success:false, refused:true, error:"Query is not sufficiently specified …"}`. 🚨 **A refusal is not a zero.** It carries no `count` and no `results` — it answers nothing. Never report one as "no matches"; re-issue it with an anchor. On a render path the anchor is the difference between one schema and all of them: an unanchored query becomes a `UNION ALL` over every partition schema. Measured on the notification bell at **4 476 rows across 201 of 201 schemas, 9–10 s per render, filtered to 0 rows in memory** on an idle replica — [Cross-Schema Fan-Out Elimination](@/Doc/Architecture/CrossSchemaFanOutElimination). ## 3. 🚨 Two queries, NEVER a `namespace:A|B` alternation A single concrete `namespace:` folds into the parsed query'…
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