According to the books online http://msdn.microsoft.com/en-us/library/ms177443.aspx
:
"In a clustered index, the leaf nodes contain the data pages of the
underlying table."
Which agrees with your assertion.
From a performance perspective, it DOES work very well. Which is why
I keep hoping for it to show up in PostgreSQL.
On Jul 16, 2009, at 2:21 PM, Scott Carey wrote:
I could be wrong, but I think MSSQL only keeps the data specified in
the
index in the index, and the remaining columns in the data.
That is, if there is a clustered index on a table on three columns
out of
five, those three columns in the index are stored in the index,
while the
other two are in a data portion. But it has been several years
since I
worked with that DB.
They are certainly storing at least those columns in the index
itself. And
that feature does work very well from a performance perspective.
IOT in Oracle is a huge win in some cases, but a bit more clunky for
others
than Clustered Indexes in MSSQL. Both are highly useful.
On 7/16/09 10:52 AM, "Justin Pitts" <justinpitts@xxxxxxxxx> wrote:
ISTR that is the approach that MSSQL follows.
Storing the full tuple in an index and not even having a data only
page
would also be an interesting approach to this (and perhaps simpler
than a
separate index file and data file if trying to keep the data in the
order of
the index).
--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
