Error with extended query protocol

[hlinnaka]

postgres=# create table tbl(i int4);
CREATE TABLE
postgres=# select * from tbl  \bind \g
ERROR:  unrecognized node type: 1189775888

See https://github.com/duckdb/pg_duckdb/blob/177b12b7a39fc14e9c0ffb136c8c9c957dc3f2d7/src/pgduckdb_planner.cpp#L91

The problem is that the type stored in custom_private is supposed to be a copyable Node type, which the duckdb connection and prepared query types are not.

[JelteF]

Basically all clients use the extended query protocol. So we should definitely fix this.

[mkaruza]

Agree with @JelteF this should be fixed asap. Simplest, most straight forward solution would be to fix this once we would have one duckdb singleton wrapper object per process - than we would not need to pass this objects around for each query.

[Tishj]

@JelteF

		// FIXME: TextDatumGetCstring allocates so it needs a
		// guard, but it's a macro not a function, so our current gaurd
		// template does not handle it.

That is possible, it's just a bit uglier:

return duckdb::Value(PostgresFunctionGuard<char*>([](Datum val) { return TextDatumGetCString(val); }, value);