Struct emptySchemaRowSet

server/flightclient/flight_executor.go:614–616

emptySchemaRowSet is returned when a query produces no data rows but does have schema information (e.g., SELECT ... LIMIT 0). This preserves column names and types for callers like COPY FROM STDIN that need to inspect the target table schema.

// package's S3CacheControl capability, backing the `duckgres.s3_cache`
// session GUC. Unlike the best-effort teardown actions above, errors are
// surfaced: a SET that did not take effect on the worker must fail, not
// silently leave the session in the wrong cache state. Workers running an
// image that predates the action reject it with Unimplemented, which also
// surfaces as an error.
func (e *FlightExecutor) SetS3CacheEnabled(ctx context.Context, enabled bool) (err error) {
	if e.dead.Load() {