On 15 June 2013 12:25, Hannu Krosing <hannu@2ndquadrant.com> wrote:
> additionally it *could* have the property Simon proposed earlier
> of *uncompressed* pages having some predetermined size, so we
> could retain optimisations of substring() even on compressed TOAST
> values.
That wasn't about having fixed size pages, it was about having a
function to determine the split points. Reason being we want to use
some intelligence to split up JSON and XML documents.
I would also like to be able to do other types of processing on fields
before they are stored.
That is probably best done as a sequence of processing transforms,
rather than a single compression module.
--Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services