#24 Postgres-XL with Npgsql

[mason_s]

There is a problem using Postgres-XL with Npgsql, discovered with prepared statements.

Per user report:

it appears that when row description of a prepared statement is provided from the coordinator to the client, that the coordinator for protocol version 3 is setting the "formats" value to (1) - which is BINARY. The datanode passes back tuples in TEXT which are then forwarded to the client. The client attempts to parse them in BINARY - which then fails.

It appears that by default, postgresql will report the fields of a prepared statement as type "text" - however, they are actually encoded binary. This explains the difference between Postgres-Vanilla and Postgres-XL. In Postgres-XL, the prepared schema reports in "text" and actually is encoded text (passthrough tuples from the datanode). So, the reported format is correct but the driver tries to account and assumes it's really binary.

To resolve, we may need to have the coordinator encode the tuples into binary.