Re: Grouped Index Tuples / Clustered Indexes

Added to TODO:

o Add more logical syntax CLUSTER table ORDER BY index;
support current syntax for backward compatibility

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Simon Riggs wrote:
> On Sun, 2007-03-11 at 11:22 +0000, Heikki Linnakangas wrote:
> > Gregory Stark wrote:
> > >> On Wed, 2007-03-07 at 10:32 +0000, Heikki Linnakangas wrote:
> > >>> I've been thinking
> > >>> we should call this feature just Clustered Indexes
> > >
> > > So we would have "clustered tables" which are tables whose heap is ordered
> > > according to an index and separately "clustered indexes" which are indexes
> > > optimized for such tables?
> >
> > Yes, that's what I was thinking.
> >
> > There's a third related term in use as well. When you issue CLUSTER, the
> > table will be clustered on an index. And that index is then the "index
> > the table is clustered on". That's a bit cumbersome but that's the
> > terminology we're using at the moment. Maybe we should to come up with a
> > new term for that to avoid confusion..
>
> First thought: we can use the term "cluster*ing* index" for CLUSTER and
> use the term "clustered" to refer to what has happened to the table and
> the index. That will probably be confused with high availability
> clustering, so perhaps not.
>
> Better thought: say that CLUSTER requires an "order-defining index".
> That better explains the point that it is the table being clustered,
> using the index to define the physical order of the rows in the heap. We
> then use the word "clustered" to refer to what has happened to the
> table, and with this patch, for the index also.
>
> That way we can have new syntax for CLUSTER
>
> CLUSTER table ORDER BY indexname
>
> which is then the preferred syntax, rather than the perverse
>
> CLUSTER index ON table
>
> which gives the wrong impression about what is happening, since it is
> the table that is changed, not the index.
>
> - - -
>
> - Are you suggesting that we have an explicit new syntax
>
> CREATE [UNIQUE] CLUSTERED INDEX [CONCURRENTLY] fooidx ON foo (....) ...
>
> or just that we refer to this feature as Clustered Indexes?
>
> - Do we still need the index WITH option, in either case?
>
> - Do you think that all Primary Keys should be clustered?
>
> - Are you thinking to rename docs, catalog etc to reflect the new
> naming/meaning?
>
> My thinking would be: CLUSTERED, no, yes, yes
> but I'd like to know what you think?
>
> --
> Simon Riggs
> EnterpriseDB http://www.enterprisedb.com
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://www.enterprisedb.com

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