Re: Index-only quals

Greg Stark wrote:
> On Fri, Aug 21, 2009 at 12:43 PM, Heikki
> Linnakangas<heikki.linnakangas@enterprisedb.com> wrote:
>> Here is an updated version of my patch to return data from b-tree
>> indexes, and use it to satisfy quals.
> 
> +             if (!found_clause && useful_pathkeys == NIL && !useful_predicate)
> +                 ipath->scantype = ST_INDEXSCAN;
> +             else
> +             {
> +                 ipath->scantype = 0;
> +                 if (index->amhasgettuple)
> +                     ipath->scantype |= ST_INDEXSCAN;
> +                 if (index->amhasgetbitmap)
> +                     ipath->scantype |= ST_BITMAPSCAN;
> +             }
> +
> 
> 
> Does this section need to check amhasgettuple for the index-only scan
> case as well? It looks like right now if an indexam has amregurgitate
> set but not amhasgettuple then weird things could happen.

We check earlier in the function before we construct indexonlyQuals that
the index has amhasgettuple. Hmm, can you find an easier-to-understand
way to write that?

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