Re: an index question

dcruncher4@aim.com wrote: > In article <fle19n011r2@drn.newsguy.com>, dcruncher4@aim.com says... > >> create index aaaa on table(col1 asc, col2 desc, col3 asc)>> >> The performance gain on the view was incredible. >> What can be the reason behind it. Can anyone explain >> the internals behind it. >> >> The only problem I see is that with this index I can not >> create a PKY or a unique constraint, and for that I am >> forced to create another index. >> > > I take it back. PKY can be created on an index with > desc columns but not as part of create table syntax. > Index has to be created first explicitly and then > PKY should be created. IDS will use the same > index. > Correct. > Does that mean that there is some sort of a bug > here because one way of creating PKY allows > desc index to be used, while the other one does > not. > Not a bug. Likely just a design decision. The Primary Key syntax doesn't allow for specifying the order of each column whether it's within the CREATE TABLE statement or outside it. You can only use a partially or wholly descending index for a primary key by creating the index first. Art S. Kagel > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list > >