lh-migrations SKILL.md skillA
lh-migrations 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-migrations@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-migrations/SKILL.md- Versions recorded
- 1
- Latest version
- v1.1, committed Oct 14, 2026
- Size
- 7,257 bytes
- Repository stars
- 2
- License
- Apache-2.0
Changing a schema that already holds real data: expand/contract, reversible steps, backfills that don't lock, and stating what a deploy strategy must respect. Trigger: load when altering an existing table, renaming or dropping anything, backfilling data, or when a release couples code to a schema change.
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
_Engine facts here were verified against PostgreSQL 11–17 semantics (September 2026). What a given operation locks, and for how long, is a property of the engine AND the version — re-check before teaching it as current._ ## Critical Patterns ### 1. Expand, migrate, switch, contract — never rename in place The rename is the trap: it makes old code and new code mutually exclusive, so there is a moment where one of them is broken no matter the deploy order. Instead: **expand** (add the new column/table, nothing reads it yet), **migrate** (write to both, backfill the old rows), **switch** (reads move to the new shape), **contract** (stop writing the old, then drop it — in a later release). Each step is deployable alone and revertible alone. The sequence is slower and it is the only version that can be undone on a Friday. ### 2. A migration coupled to a deploy is a rollback you cannot do If rolling back the code requires rolling back the schema, you have no rollback — restoring a schema means restoring data written since. Schema changes go out BEFORE the code that needs them and stay backward-compatible with the currently …
Read the whole file at its exact version.
How to install
mdr add jrodrigopuca/local-agents/lh-migrations@sha256:55ebfefbfa3b8809The 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_q3xwzxj526yrypjx)
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 (7257 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_q3xwzxj526yrypjx GET https://markdownregistry.com/api/v1/resolve?ref=jrodrigopuca/local-agents/lh-migrations GET https://markdownregistry.com/api/v1/blob/55ebfefbfa3b88098aeec8221fcbd3615bd2969e068ccda8dba63d6ae1ef0717
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.