Thread: HOT WIP Patch - Version 5.0

The version 5.0 of HOT WIP patch is posted on pgsql-patches. This
fixes the VACUUM FULL issue with HOT. In all the earlier versions,
I'd disabled VACUUM FULL.

When we move the HOT-chain, we move the chains but don't carry
the HOT_UPDATED or HEAP_ONLY flags and insert as many index
entries as there are tuples in the chain. IOW the HOT-update
is actually turned into a COLD chain.

Apart from this, I'd to make some changes to the VACUUM FULL
code so that the number of indexed tuples is counted
correctly. With HOT, whenever a HEAP_ONLY tuple is moved, an
additional index entry is generated and this needs to be
taken into account.

Please let me know comments/suggestions.


Thanks,
Pavan

-- 


EnterpriseDB        http://www.enterprisedb.com

On Wed, 2007-03-21 at 11:27 +0530, Pavan Deolasee wrote:

> The version 5.0 of HOT WIP patch is posted on pgsql-patches. This
> fixes the VACUUM FULL issue with HOT. In all the earlier versions,
> I'd disabled VACUUM FULL.
> 
> When we move the HOT-chain, we move the chains but don't carry
> the HOT_UPDATED or HEAP_ONLY flags and insert as many index
> entries as there are tuples in the chain. IOW the HOT-update
> is actually turned into a COLD chain.

Seems fine to me.

> Apart from this, I'd to make some changes to the VACUUM FULL
> code so that the number of indexed tuples is counted
> correctly. With HOT, whenever a HEAP_ONLY tuple is moved, an
> additional index entry is generated and this needs to be
> taken into account.

It should do this, but its probably worth posting a TODO of minor items
like this, otherwise we'll lose focus on the major items.

--  Simon Riggs              EnterpriseDB   http://www.enterprisedb.com

Well, I didn't add anything new here. VACUUM validates the
number of index entries and heap entries. With HOT I had to
adjust things properly.

Thanks,
Pavan


--

EnterpriseDB     http://www.enterprisedb.com