Hello, I need to perform "conversions" (transcoding) between BYTEA and TEXT columns in a UTF-8 database. I searched for existing solutions and was unable to find one for 8.x or 9.x, so I cam up with something I'd like to validate with the more enlightened members of this list... Case 1: reinterpreting: (Working on a 8.4.3 backend.) In a UTF8 database I have a BYTEA value which contains a perfectly valid UTF8 string. I want to simply *reinterpret* it as TEXT (in the same way pg_convert_from internally reinterprets the BYTEA return value from pg_convert as TEXT), backend-side, no transcoding/encoding/decoding should take place. The solution I came up with goes something like this: CREATE DOMAIN my_varlena AS bytea; CREATE CAST (my_varlena AS text) WITHOUT FUNCTION; ... SELECT bytea_col::my_varlena::text FROM tbl; -- bypass the bytea to varchar/text conversion which actually calls encode() ... DROP DOMAIN my_varlena CASCADE; Is there anything blatantly wrong with this approach that I have missed, or is there a more straightforward way, or anything to be improved? (Again, I need a backend-side solution, not a client-side one -- e.g. copying huge amounts of data from a BYTEA column to a TEXT column in some other table.) Case 2: converting: (Working on a 8.4.3 backend.) In a UTF8 database I have a BYTEA value which contains a perfectly valid e.g. LATIN1 string. Building on top of the above (again, 100% backend-side), is there anything blatantly wrong with: CREATE DOMAIN my_varlena AS bytea; CREATE CAST (my_varlena AS text) WITHOUT FUNCTION; ... SELECT convert(bytea_col::bytea, 'LATIN1', 'UTF8')::my_varlena::text FROM tbl; ... DROP DOMAIN my_varlena CASCADE; Thank you! PS: Incidentally, if bytea_col contains any of the invalid LATIN1 sequences 0x7f, 0x80, 0x81, 0x82 etc., pg_convert (v8.4.3) will (leniently) convert them to the invalid UTF-8 BYTEA sequences 0x7f, 0xc2 0x80, 0xc2 0x81, 0xc2 0x82 etc. :) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
