Hi, I have two tables into which I dump mail statistics.  The two tables are:

create table attachments (
  id text,
  attachment text
);
create table mail (
  id text,
  size int,
  whofrom text,
  subject text,
  date datetime,
  inout char
);

The table mail holds information about each mail message.  The table attachments holds 
the name of any attachments.  Linking the attachment(s) and the message is the id.

I want to delete all records relating to mail that is over two months old.  I tried:

select count(*) from attachments a where a.id in (select m.id from mail m where m.date 
< now()-62);

but ran out of swap.  The mail table is 19Mb, the attachment one 1Mb.  I was up to 
380Mb of swap used on a machine with 128Mb RAM, and over 15 minutes run time.  At that 
point I killed the query.

I next tried is as follows:

drop table temp;
select id into temp from mail where date < now()-62;
delete from attachments where id in (select id from temp);
delete from mail where date < now()-62;

This worked fine and deleted the records as intended in a few minutes.  Can anyone see 
why the initial query ate so much swap?


Cheers
Kevin
[EMAIL PROTECTED]

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