2010/1/18 Tom Lane <tgl@xxxxxxxxxxxxx>: > Greg Smith <greg@xxxxxxxxxxxxxxx> writes: >> Craig Ringer wrote: >>> For those non-Oracle users among us, what's an external table? > >> External tables let you map a text file directly to a table without >> explicitly loading it. In PostgreSQL, if you have data in a CSV file, >> usually you'd import it with COPY before you'd use it. If external >> tables were available, you'd just say there's an external table as a CSV >> file and you could start running queries against it. > > I'm finding it hard to visualize a use-case for that. We must postulate > that the table is so big that you don't want to import it, and yet you > don't feel a need to have any index on it. Which among other things > implies that every query will seqscan the whole table. Where's the > savings? > > 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 > Another case, Tom, could be when the file is updated from a non-DB application and you need to synchronize the data with other DB applications ... -- Vincenzo Romano NotOrAnd Information Technologies NON QVIETIS MARIBVS NAVTA PERITVS -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
