lh-query-performance SKILL.md skillA
lh-query-performance from jrodrigopuca/local-agents is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jrodrigopuca/local-agents/lh-query-performance@v1.1Pins v1.1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jrodrigopuca/local-agents
- Path
dba/skills/lh-query-performance/SKILL.md- Versions recorded
- 1
- Latest version
- v1.1, committed Oct 14, 2026
- Size
- 4,495 bytes
- Repository stars
- 2
- License
- Apache-2.0
Making reads cheap by design: execution plans, index strategy, N+1 detection, and diagnosing slowness against real cardinality instead of guessing. Trigger: load when a query or page is slow, when designing the access paths a feature needs, or when deciding whether an index is worth its cost.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
## Critical Patterns ### 1. Read the plan before touching anything The execution plan is the only source of truth about what the database actually does — everything else is a theory. Get it with real parameters against production-like volume, and read it for three things: what it scans, what it sorts, and where the row estimate diverges from reality. A plan whose estimate says 12 rows where 400,000 arrive explains the slowness by itself, and no index added on a hunch will fix a query you haven't looked at. This is the [evidence ladder](../../../generalist/skills/lh-verification/SKILL.md) applied to performance: measured, not assumed. ### 2. Indexes are a write tax paid for a read discount Every index makes writes slower and consumes space; it earns that by turning a scan into a lookup. So the question is never "would an index help this query" but "does this query matter enough to tax every insert on the table". Index the access paths the product actually depends on, drop the ones nothing uses, and know that an unused index is pure cost with no benefit — invisible until you look for it. ### 3. Composite index order is decided by the predicate, not by taste …
Read the whole file at its exact version.
How to install
mdr add jrodrigopuca/local-agents/lh-query-performance@sha256:bf4445b98cb0d908The line at the top of this page pins the label v1.1, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_npwzmmyldyhzumig)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Oct 14, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4495 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
jrodrigopuca/local-agents · 2 stars · license Apache-2.0 · pushed 2026-10-23 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_npwzmmyldyhzumig GET https://markdownregistry.com/api/v1/resolve?ref=jrodrigopuca/local-agents/lh-query-performance GET https://markdownregistry.com/api/v1/blob/bf4445b98cb0d908aa55661427a90ad222b5cfc777c25c65f2e0b954c58e919a
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.