Alias SPSN
A struct to represent specializations of prepared statement parameters.
If you need to send large objects to the database it might be convenient to
send them in pieces. The chunkSize and chunkDelegate variables allow for this.
If both are provided then the corresponding column will be populated by calling the delegate repeatedly.
The source should fill the indicated slice with data and arrange for the delegate to
return the length of the data supplied (in bytes). If that is less than the chunkSize
then the chunk will be assumed to be the last one.
Please use one of the aliases instead of the Impl struct, as this name likely will be removed without deprecation in a future release.