Re: [PATCH] Use idiomatic style for varlena structs

Jay Levitt <jay.levitt@gmail.com> writes:
> I'm new to the codebase, but I think this patch reflects real-world usage;
> the PostgreSQL code itself always calls the length field "vl_len_", and I
> believe int32 is preferred over int4 (yes?)

The point of calling it vl_len_ is that it should never be referenced by
that name, so I'm not sure that propagating that name into user
documentation is a good idea.  I do agree with the part of this patch
that recommends use of SET_VARSIZE.

For context, the issues you're concerned about only matter when dealing
with a toastable datatype (not all varlena types are toastable).  The
particular bit of docs here doesn't pretend to be explaining how to
write toast-safe code.  I think it might be better from an expository
standpoint to cover that separately, rather than try to work it into the
very first pass over the concepts.

            regards, tom lane