Re: Requesting clarification on Vacuuming/Freezing behaviour

Gokulakannan Somasundaram wrote:
> a) When i was looking at the code for freezing heap tuples, i found out the
> following. While freezing we log the complete block(not just the tuples we
> froze).
> b) Again after removing the dead tuples and fragmentation, we log the
> complete block.

Umm, no we don't. In log_heap_freeze, we log an array of offsets, of 
those tuples that were frozen.

Perhaps you're been confused by full page writes? If a block hasn't been 
modified by last checkpoint, then we do log the whole page for any 
operation, including vacuuming and freezing. (except setting hint bits).

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com