Add list of DB migrations to docs
## Proposed Changes
Add a list of schema version changes to the book.
I hope this will be helpful for users upgrading to v2.5.0, to know that they can downgrade to schema v9 to run v2.3.0/v2.4.0 or to schema v8 to run v2.2.0/v2.1.0.
@@ -12,15 +12,29 @@ command for applying database downgrades.
**Everything on this page applies to the Lighthouse _beacon node_, not to the
validator client or the slasher**.
+## List of schema versions
+
+| Lighthouse version | Release date | Schema version | Downgrade available? |
+|--------------------|--------------|----------------|----------------------|
+| v2.0.0 | Oct 2021 | v5 | no |
+| v2.1.0 | Jan 2022 | v8 | no |
+| v2.2.0 | Apr 2022 | v8 | no |
+| v2.3.0 | May 2022 | v9 | yes (pre Bellatrix) |
+| v2.4.0 | Jul 2022 | v9 | yes (pre Bellatrix) |
+| v2.5.0 | Aug 2022 | v11 | yes |
+
+> **Note**: All point releases (e.g. v2.3.1) are schema-compatible with the prior minor release
+> (e.g. v2.3.0).
+
## How to apply a database downgrade
To apply a downgrade you need to use the `lighthouse db migrate` command with the correct parameters.
1. Make sure you have a copy of the latest version of Lighthouse. This will be the version that
knows about the latest schema change, and has the ability to revert it.
-2. Work out the schema version you would like to downgrade to by checking the Lighthouse release
- notes. E.g. if you want to downgrade from v2.3.0, which upgraded the version from v8 to v9, then
- you'll want to _downgrade_ to v8 in order to run v2.2.x or earlier.
+2. Work out the schema version you would like to downgrade to by checking the table above, or the
+ Lighthouse release notes. E.g. if you want to downgrade from v2.3.0, which upgraded the version
+ from v8 to v9, then you'll want to _downgrade_ to v8 in order to run v2.2.x or earlier.
3. **Ensure that downgrading is feasible**. Not all schema upgrades can be reverted, and some of
them are time-sensitive. The release notes will state whether a downgrade is available and
whether any caveats apply to it.
