Re: Oracle 11g Virtual Columns?
From: Michael Austin <maustin_at_firstdbasource.com>
Date: Mon, 19 Jan 2009 15:54:13 -0600
Message-ID: <cE6dl.9109$hc1.4977_at_flpi150.ffdc.sbc.com>
Connor McDonald wrote:
>> I have read various articles on virtual columns? I still do not
>> understand their advantages other than they save some disk space, One
>> can put logic of virtual columns in a trigger which will save
>> information in a real column. Real column will need some additional
>> disk space, but it will save some cpu time when one is doing slelects
>> on “virtual” columns.
Date: Mon, 19 Jan 2009 15:54:13 -0600
Message-ID: <cE6dl.9109$hc1.4977_at_flpi150.ffdc.sbc.com>
Connor McDonald wrote:
> zigzagdna_at_yahoo.com wrote:
>> I have read various articles on virtual columns? I still do not
>> understand their advantages other than they save some disk space, One
>> can put logic of virtual columns in a trigger which will save
>> information in a real column. Real column will need some additional
>> disk space, but it will save some cpu time when one is doing slelects
>> on “virtual” columns.
> > Well, they're columns...so lots of goodies just in that, eg constraints > (foreign key, not null, unique, primary key), optimizer stats, fgac, etc > etc
Although, you would need your head examined if you did use it for a PK/FK. It makes no sense... as the values could potentially change. Received on Mon Jan 19 2009 - 15:54:13 CST