data-migration SKILL.md skillA
data-migration from okhp3/skillz is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add okhp3/skillz/data-migration@git:20260828.866dec6Pins git:20260828.866dec6 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- okhp3/skillz
- Path
community/data-migration/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260828.866dec6, committed Aug 28, 2026
- Size
- 5,217 bytes
- Repository stars
- 3
- License
- MIT
Changes a schema or moves data in production without downtime or loss — column changes, backfills, table splits, and system-to-system moves. Use this whenever the user is writing a migration, altering a table, backfilling data, renaming a column, or moving data between systems. Treat it as required reading before any migration runs against a database with real data. For designing the schema, use data-modeling.
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
# Data migration Migrations are the most irreversible thing most engineers do routinely. Code can be rolled back; a dropped column cannot, and a botched backfill can corrupt data in ways no deploy fixes. Two properties make a migration safe, and both must hold: - **Backwards compatible:** the currently deployed code works before *and* after it runs - **Reversible, or backed up:** you can get back, or you have a copy you have tested restoring If a migration has neither, it needs a maintenance window and a rehearsal. ## 1. Never combine schema change with data change Separate migrations, separate deploys: 1. Add the new structure 2. Backfill it 3. Switch the code to use it 4. Remove the old structure — later, as its own change Combining these makes rollback impossible: reverting the code leaves the data half-moved, and reverting the data loses whatever the new code wrote. **Done when:** each step is independently deployable and revertible. ## 2. Use expand-then-contract for anything breaking Renaming a column is not a rename in production. It is: 1. **Expand** — add `new_name`, nullable 2. **Dual-write** — deploy code writing both; reads still use the old …
Read the whole file at its exact version.
How to install
mdr add okhp3/skillz/data-migration@sha256:2a33c8fae2b6dfaeThe line at the top of this page pins the label git:20260828.866dec6, 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_sjvpgesjmc5rarfr)
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Versions
The registry has recorded 1 version of this file, committed on Aug 28, 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 (5217 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
okhp3/skillz · 3 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_sjvpgesjmc5rarfr GET https://markdownregistry.com/api/v1/resolve?ref=okhp3/skillz/data-migration GET https://markdownregistry.com/api/v1/blob/2a33c8fae2b6dfae60a579f83bb326b783f0052f325f55604c7b8ae8aa700fd1
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.