am Sun, dem 28.01.2007, um 10:25:33 -0600 mailte Ron Johnson folgendes: > Hi. > > These fields do not use any disk space, as the data in them is > derived on the fly. > > For example: > CREATE TABLE T_EXAMPLE ( > SOME_DATE DATE, > JDATE COMPUTED BY EXTRACT(JULIAN FROM SOME_DATE) > ); > > A work-around is to create a function, and reference it in every > query, but storing them in the table definition is the "tidy", > low-maintenance way to do it.
Was this a question how to do this in PostgreSQL? You can use a VIEW. Just create T_EXAMPLE ( SOME_DATE DATE ); and then CREATE VIEW view_example AS SELECT some_date, EXTRACT(JULIAN FROM some_date) AS julian_date FROM T_EXAMPLE; Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
