Re: Whatcha' wanta have?????
"Jonathan Leffler" <jleffler@earthlink.net> wrote in message news:402EEA68.9010107@earthlink.net... > Serge Rielau wrote: > > Neil Truby wrote: > >> "Serge Rielau" <srielau@ca.eye-be-em.com> wrote: > >>> Andrew Hamm wrote: > >>>> Mark Denham wrote: > >>>>> Some indexing additions: > >>>>> > >>>>> 1) Inclusion of columns in the index that are not part of the index > >>>>> key but help speed processing. This feature is available in a number > >>>>> of other rdbms's. > >>>> > >>>> Waaaaaa? Please explain? > >>> > >>> This feature applies to unique indexes. > >>> Let's presume you have an employee table. The PK is empno. > >>> You want to optimize lookups of employee names by empno. > >>> Without this feature the fastest to do this (assuming a non trivial > >>> table size) is to fetch the rowid from the index and then do an fetch by > >>> rowid from the table to get the name. > >>> If you INCUDE empname in the unique index then you save the the table > >>> access. [...strike incorrect sentence...] > > I don't see that it has to apply solely to unique indexes. It > basically allows a key-only scan to also pick up the other critical > data without having to fetch the data page. So, if you've got a table > of zip-codes and state codes, you index on the zip-code - which > probably needs to be unique - and include the state code too, and you > never have to go to the table which contains demographic data stored > in blobs for the state code. > > The Orrible database has a feature along these lines, I believe. This is also a feature of DB2..
"Madison Pruet" <mpruet@comcast.net> wrote in message news:rmOXb.324282$na.477931@attbi_s04... > > "Jonathan Leffler" <jleffler@earthlink.net> wrote in message > news:402EEA68.9010107@earthlink.net... > > Serge Rielau wrote: > > > Neil Truby wrote: > > >> "Serge Rielau" <srielau@ca.eye-be-em.com> wrote: > > >>> Andrew Hamm wrote: > > >>>> Mark Denham wrote: > > This is also a feature of DB2.. Madison, could we try to avoid turning this thread into an "us-vrs-them" thread? :-)
Ouch! ;-) Actually I was pointing out to Jonathan that we might need this functionality. ;-) M.P. "Neil Truby" <neil.truby@ardenta.com> wrote in message news:c0ohod$18dn12$1@ID-162943.news.uni-berlin.de... > "Madison Pruet" <mpruet@comcast.net> wrote in message > news:rmOXb.324282$na.477931@attbi_s04... > > > > "Jonathan Leffler" <jleffler@earthlink.net> wrote in message > > news:402EEA68.9010107@earthlink.net... > > > Serge Rielau wrote: > > > > Neil Truby wrote: > > > >> "Serge Rielau" <srielau@ca.eye-be-em.com> wrote: > > > >>> Andrew Hamm wrote: > > > >>>> Mark Denham wrote: > > > > This is also a feature of DB2.. > > Madison, could we try to avoid turning this thread into an "us-vrs-them" > thread? :-) > >
Madison Pruet wrote: > Ouch! ;-) > > Actually I was pointing out to Jonathan that we might need this > functionality. ;-) How's about he signs off on that if you can make the other members of the planning committee give him the logged TRUNCATE?