Re: CREATE INDEX and HOT - revised design - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: CREATE INDEX and HOT - revised design
Date
Msg-id 200703211739.l2LHdqT11905@momjian.us
Whole thread Raw
In response to Re: CREATE INDEX and HOT - revised design  (Bruce Momjian <bruce@momjian.us>)
Responses Re: CREATE INDEX and HOT - revised design  ("Pavan Deolasee" <pavan.deolasee@gmail.com>)
List pgsql-hackers
Effectively, my idea is not to chill/break the HOT chains during index
creation, but rather to abandon them and wait for VACUUM to clean them
up.

My idea is much closer to the idea of a bit per index on every tuple,
except the tuple xmax and pg_index xid replace them.

---------------------------------------------------------------------------

Bruce Momjian wrote:
> Pavan Deolasee wrote:
> > On 3/21/07, Bruce Momjian <bruce@momjian.us> wrote:
> > >
> > >
> > >
> > > I am worried that will require CREATE INDEX to wait for a long time.
> > 
> > 
> > 
> > Not unless there are long running transactions. We are not waiting
> > for the lock, but only for the current transactions to finish.
> 
> Waiting for all transactions might take a while, no?
> 
> > > Is the pg_index xid idea too complex?  It seems to give you the
> > > per-tuple index bit, without the restrictions.
> > 
> > 
> > 
> > How do we handle HEAP_ONLY tuple cleanup ? If I understood
> > the proposal correctly, at the end of the create index, a HEAP_ONLY
> > tuple may have pointer from the new index, isn't it ?
> 
> Right.  You would need vacuum to clean up the HEAP_ONLY tuples.  I just
> sent an email about those deails.  We might have autovacuum check
> pg_index and do it automatically.
> 
> -- 
>   Bruce Momjian  <bruce@momjian.us>          http://momjian.us
>   EnterpriseDB                               http://www.enterprisedb.com
> 
>   + If your life is a hard drive, Christ can be your backup. +
> 
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--  Bruce Momjian  <bruce@momjian.us>          http://momjian.us EnterpriseDB
http://www.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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