> 1. The DPB
>
> This is certainly an area where the developer is required to manipulate
> something in a way that is very clumsy and error prone.

In my Delphi programs, connecting to the database consists of two statements:

dpb := isc_dpb_version1 +
FormatPBParam(isc_dpb_user_name, User.Text) +
FormatPBParam(isc_dpb_password, Pwd.Text) +
FormatPBParam(isc_dpb_sql_role_name, Role.Text);

isc_attach_database(status_vector, 0, db_name, Fdb, Length(dpb), dpb);

(where helper function FormatPBParam() contains single statement)
I can't imagine anything simpler :)

> 2. The XSQLDA

...

> isc_dsql_allocate_xsqlda(XSQLDA **xsqlda, unsigned short xsqlda_size)
>
> This function would allocate the initial XSQLDA with some reasonable size
> if none
> was specified.

But XSQLDA is client side sturcture, and different programing environments
can prefere different memory managers.

> isc_dspl_prepare_xsqlda(XSQLDA *xsqlda)
>
> This function would handle all of the required memory allocation for both
> information
> and data. An additional null byte would be allocated for string based
> data.

FB does not retrieve data as zero terminated string,
and not all languages use such "structure" either.

> char *isc_dsql_get_name(XSQLDA *xsqlda, unsigned short colno)

Do you mean name of the column ? It is stored in xsqlda, just read it. In Delphi it is just

Copy(xsqlda.sqlvar[col].sqlname, 1, xsqlda.sqlvar[col].sqlname_length)

> short isc_dsql_get_type(XSQLDA *xsqlda, unsigned short colno)

Type of the column ? You can read it directly from xsqlda, what else is such function
expected to do ? In delphi it is just

xsqlda.sqlvar[col].sqltype and $FFFFFFFE

> void *isc_dsql_get_bytes(XSQLDA *xsqlda, unsigned short colno)
> char *isc_dsql_get_string(XSQLDA *xsqlda, unsigned short colno)

So these functions would allocate memory for result ? It can be awkward
for some languages.

> long isc_dsql_get_long(XSQLDA *xsqlda, unsigned short colno)
> ...

You omitted the more complicated scaled numbers and date/time
(because support for such types vary between different languages)

Ivan