Thread

Re: [HACKERS] sorting big tables :(

Michael Richards <miker@scifair.acadiau.ca> — 1998-05-16T15:47:52Z

On Fri, 15 May 1998, Bruce Momjian wrote:

> > I have a big table. 40M rows.
> > On the disk, it's size is:
> >  2,090,369,024 bytes. So 2 gigs. On a 9 gig drive I can't sort this table.
> > How should one decide based on table size how much room is needed?

> It is taking so much disk space because it is using a TAPE sorting
> method, by breaking the file into tape chunks and sorting in pieces, the
The files grow until I have 6 files of almost a gig each. At that point, I
start running out of space...
This TAPE sotring method. It is a simple merge sort? Do you know of a way
this could be done while using constant space and no more complexity in
the algorithim. Even if it is a little slower, the DBMS could decide based
on the table size whether it should use the tape sort or another one...
Bubble sort would not be my first choice tho :)

-Mike