On 2020-Nov-24, Andy Fan wrote:
> then we modified the copy/read/out functions for this node. In
> _readFuncExpr,
> we probably add something like
> [ ... ]
> Then we will get a compatible issue if we create a view with the node in
> the older version and access the view with the new binary.
When nodes are modified, you have to increment CATALOG_VERSION_NO which
makes the new code incompatible with a datadir previously created -- for
precisely this reason.