Re: request for enhancement: 2K -> 4K

The default page size in XPS (8.x) is 4K. Dave In article <6791pn$3k5@cssun.mathcs.emory.edu>, jon@syscom.etcscan.com says... > >At 11:49 AM 12/15/97 +0000, you wrote: >}David Williams wrote: >} >}> In article <3494a300.1118117@news.xs4all.nl>, Reinoud van > Leeuwen >}> <reinoud@xs4all.nl> writes >}> >On 12 Dec 1997 09:26:16 -0700, Pablo Sanchez <pablo@sgi. >com> wrote: >}> > >}> >>Sybase Inc., >}> >> >}> >>I'd like to request that we increase the atomic page si >ze >}> >>from 2K to 4K. Today's systems I/O subsystems can hand >le >}> >>the larger page sizes. It'd be nice to have pages grea >ter >}> >>than 2K for DSS type of applications. OLTP, I don't >}> >>believe, would suffer. (Informix uses a 4K page size a >nd >}> >>they do pretty well...) with DSS app's, one has >}> >>denormalization that tends to create fat rows... how a >bout >}> >>it? >}> > >}> >The disadvantage is that 4 K will be the minumum size fo >r all >}> >allocations, resulting in more wasted space in the datab >ase... >}> >_______________________________________ >}> >}> With 2Gb (2048Mb) even wasting 20Mb is only 1%! Surely >you don't >}> size things that 1% more will mean you need to buy anot >her disk? >}> >}> I come from tge Informix side and I'd like things simil >ar to >}> Informix's blobspaces. You have normal database spaces >which have >}> 2K or 4K pages depending upon the specific port. within > blobspaces >}> you then define how large a blobpage will be in units o >f either >}> 2K or 4K. Big buffers (up to, I think 32K) are using to > access >}> blobspaces. >}> >}> Why can't we just define our own page sizes for each ar >ea of disk >}> we use? Say in units of 2K or 4K depending upon the mac >hine type? >}> >}> -- >}> David Williams >} >}The paging functions in the Informix engine were complicate >d enough to >}understand in v5.01 with only 2K pages, and I am unaware of > how much it has >}increased in the later versions, ie. 6+. I would think tha >t this would not >}be approved on the same grounds as you described above. De >veloping and >}looking after this would simply be ugh! > >As I understand it, even in pre-6.x, the page size for Infor >mix was platform >specific. Most ports were done with a 2K page, however some >which showed >performance advantages with a larger page size, were ported >as 4K. Sequent >is one example. > >Jon > >}-- >}Graeme Allison >}Technical Support Consultant >}Kenan Systems Corporation >} >} >------------------------------------------------------------ >----------- >Jon C. Vemo jon@etcscan.com >Database Administration >Deluxe Payment Protection Systems/SCAN >Bothell, WA >(425) 489-1120 >------------------------------------------------------------ >-----------