# Fork, Fix, Delete: Safe Database Migrations with GitHub Copilot and Tiger Cloud

> Source: <https://dev.to/victormawira05lgtm/fork-fix-delete-safe-database-migrations-with-github-copilot-and-tiger-cloud-45ni>
> Published: 2026-10-20 18:06:32+00:00

A safe production workflow for fixing slow time-series queries without ever touching prod.

The problem: Direct fixes on Postgres are risky. A bad index, a wrong type, or a long `ALTER TABLE` can lock production.

My solution: **Fork / Fix / Delete** using GitHub Copilot Agent Mode + Tiger Cloud MCP.

`tiger_create_fork` and cloned my live service `db-63453` into `db-63453-test` (isolated, same data)`EXPLAIN ANALYZE`, converted the table to a hypertable, fixed timestamp types to `timestamptz`, and added proper time-based indexes. Also used Tiger's Dump & Restore for migrating tables.`tiger_delete_service` — fork gone, prod untouched and still `READY`.
Who gets lazier? Any dev who is scared to touch prod DBs. The agent does the risky part in a sandbox.

**Final state — proof of Delete:**

My prod `db-63453` is READY in US East, 29 days trial left. The fork `db-63453-test` is gone. Only 1 service remains.

**Monitoring after fix:**

Checkpoint logs are clean, no lock, fatal errors were just from the fork shutdown — expected behavior.

Loom video: [https://www.loom.com/share/48bb136113c14fa881559b259e4732c4](https://www.loom.com/share/48bb136113c14fa881559b259e4732c4)

GitHub Repo: `https://github.com/your-username/tiger-fork-fix-delete`

Key files:

`mcp.json` — Tiger Cloud MCP + Docs MCP config`.github/copilot-instructions.md` — Time-series best practices (hypertable, timestamptz, btree)`fix.sql` — Before/After of slow query

```
sql
-- BEFORE: 2.3s sequential scan
EXPLAIN ANALYZE SELECT avg(value) FROM sensor_data WHERE time > now() - interval '1 day';

-- AFTER: 43ms index scan on hypertable
SELECT create_hypertable('sensor_data', 'time');
CREATE INDEX ON sensor_data (time DESC);

#postgres, #ai, #githubcopilot, #database
What's the worst production database incident you've ever accidentally caused, and how did you recover? Let me know in the comments below!
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