Appender and attached databases / temporary tables

[stromnov]

Hi! Is it possible to create an Appender for a temporary table? Or is it possible to create an Appender for a specific table in an attached database?

[taniabogatsch]

1. I know it is possible to append to temporary tables in the C++ API. Could you give it a try in go-duckdb?
2. That is currently not supported, as we cannot pass the catalog (database) when creating an appender. It will become possible once these changes are released: [Feature] Allow passing the catalog during C API appender creation duckdb/duckdb#14256

[stromnov]

A snippet from the documentation says that "temporary tables are part of the temp.main schema". Therefore, if I understand correctly, this is not currently possible. At least all my experiments ended with a message indicating an error "database/sql/driver: could not create appender: duckdb error: Table "tempname" could not be found".

[taniabogatsch]

In that case, you could check if it succeeds with the C API on duckdb's latest main. If so, we need to add the respective support here after the next release. Otherwise, we'd have to add this to duckdb first. At least I don't see a reason against supporting appends to temporary tables. 🤔