Craig Ringer <craig@xxxxxxxxxxxxxxxxxxxxx> writes: > On 7/06/2011 8:32 AM, Steve Crawford wrote: >> I am working on my final 7.4 -> 9.0 upgrade. Data-type (auto-coalesce >> and foreign-key), query and encoding issues are resolved. Dump/restore >> is tested. But... >> >> I have a few old client systems that are difficult/infeasible to update. >> I know the recommended procedure is to update clients ahead of server >> but what problems am I likely to encounter connecting to a 9.0 server >> from a 7.4 client? > Reliance on implicit casts to/from text in queries may be a problem. > You could also have issues if the clients rely on metadata obtained from > the database - for example, enumerating columns in a table or listing > tables. I know this has been an issue when using older JDBC drivers > against newer servers, and wouldn't be too surprised if similar issues > existed with libpq. libpq itself is pretty metadata-ignorant. Higher-level stuff such as python or perl DBI interfaces (or JDBC, as Craig says) would pose much more risk. At the same time, if you are sticking with a 7.4-era libpq, you're missing literally years worth of bug fixes ... and I think the compatibility risks associated with an update there are pretty minimal compared to what you're already buying into with the server-side upgrade. So my advice would be to try to relink all your old apps against more modern versions of libpq as well as any higher-level client drivers you are using. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
