>> * The Firebird JDBC driver does not have proper support for batch
>> updates, so batch updates are disabled.
> Is this still the case with Jaybird?

No, since JayBird 1.5.x.

>> * Firebird does not support auto-increment columns.
> We know these are handled differently, and that generators get round the
> problem of 'miss generating' and auto-increment.

The Statement.getGeneratedKeys() method will not be supported for FB < 2.0
that should implement the RETURNING clause for INSERTs. Will appear in
JayBird 2.1.

>> * Firebird does not support the LOWER, SUBSTRING, or INSTR SQL
>> functions, which means that toLowerCase(), indexOf(), and substring()
>> methods in JDOQL cannot be used.
> This is out of date, so what is the current state of play in relation to
> Jaybird?

LOWER and SUBSTRING are supported, I have no idea what INSTR is.

JayBird has a switch that tells it to assume that standard UDF lib is
installed and it will support those functions in escaped synatax too.

Roman