> ## Documentation Index
> Fetch the complete documentation index at: https://clisma.poorquality.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# How migrations work

> Understand how clisma tracks and validates migrations

## Migrations table

clisma records applied migrations in a ClickHouse table (default:
`schema_migrations`). Each row includes:

* `version` (timestamp prefix)
* `name` (filename suffix)
* `checksum` (sha256 of file contents)
* `hostname` (machine name that applied the migration)
* `applied_by` (user who applied the migration)
* `cli_version` (clisma CLI version)
* `applied_at` (server time)

## Checksums

If a migration file changes after being applied, clisma stops with a checksum
mismatch error. Create a new migration instead of editing the old one.