It seems that the MetaType() function for ADOdb's postgres driver (postgres64) returns some types improperly:

1) For varchars > 100cc, it returns 'X' (clob) instead of 'C' (characters)
2) For any integer (bigint, int2, int4...) belonging to one unique key it returns 'R' (sequence, serial) instead of 'I'.

While these annoyances can be changes easily in code (both in ADOdb or in our own drivers), I've asked in ADOdb forums to know if there is any reason for that:

http://phplens.com/lens/lensforum/msgs.php?id=17963

Awaiting for some response there some days... ciao :-)