<blockquote>
<p>Noted. My remaining query is on the time taken to make the column type changes in production, i.e. will we need any downtime to run the migration, or given it should (hopefully) be just a column metadata change, is it quick? Is there an easy way to find this out before we do it for real?</p>
</blockquote>
<p>The values need to be converted from one type to another. It's a trivial conversion, but it still needs to be done. Because the <code>nodes</code> table isn't partitioned that means the parallelism is limited.</p>
<p>It's probably possible to do this without an outage but not easy.</p>

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