Hi.
For the first time, I'm checking the OIDs returned
(via the result set's PQftype API), by "regular" SELECT:
`select ... from tab`
and by a COPY TO BINARY:
`COPY (
select ...
from tab
) TO STDOUT WITH (FORMAT BINARY)`
from tab
) TO STDOUT WITH (FORMAT BINARY)`
And to my surprise, they are not!
The ones from the COPY are all zeros.
Is that normal?
The BINARY record format encodes the byte-size, not the OIDs of the (scalar) fields.
How is one supposed to "infer" the OIDs then?
Also, given that the select-clause can use expressions I think,
including casts, instead of just naming columns, "describing" the table doesn't help.
But even for a "plain" COPY, having to describe explicitly is one more round-trip,
and seems asymmetrical compared to the result-set of a regular select.
I'm both surprised and confused by this behavior.
And would appreciate some clarifications. Thanks, --DD
PS: libpq v16.1. v12 server.
