PFC wrote:
> > There's a great deal about this in the list archives (probably more in
> > pgsql-hackers than in -performance).  Most of the current interest has
> > to do with building in-memory bitmaps on the fly, as a way of decoupling
> > index and heap scan processing.  Which is not quite what you're talking
> > about but should be pretty effective for low-cardinality cases.  In
> > particular it'd allow AND and OR combination of multiple indexes, which
> > we do poorly or not at all at the moment.
>       Is this called a star join ?
>       It would also allow to access the data pages in a more sequential order 
> if the rows are not required to be retrieved in index order, which would  
> potentially be a large speedup for index scans concerning more than the  
> usual very small percentage of rows in a table : if several rows to be  
> retrieved are on the same page, it would visit this page only once.

Please see the TODO list for a summary of previous discussions and

  Bruce Momjian                        |               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

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