Connector/ODBC FP conversion overhead

[David Yeowart]

We currently have a C++ application that reads significant amounts of primarily float point data from several potential data sources - MySQL included. As maintaining multiple database layers is getting problematic we're investigating dropping all but the ODBC driver, but we're having issues with Connector/ODBC performance (almost an order of magnitude slower than libmysql - and given this is the primary database we use, that's a problem).

Profiling reveals this is because data appears to be serialised to string for transmission then converted back to a binary format on the client instead of using a binary protocol (compared to the native library a nontrivial chunk of our runtime ends up being in strtold, which is being called by sql_get_data). Checking the source confirms this. While that probably doesn't matter much for most applications, it's quite problematic here - is this intended behaviour? Have we missed a flag for a more appropriate transport mechanism?