Re: A thought on Index Organized Tables

Gokulakannan Somasundaram wrote:
> OK I think, i can think of a solution to achieve fast full index scan like
> oracle.
> a) Issue ids to every block that gets created inside the index. we are
> already doing that
> b) Now before the fast full index scan starts, note down the max id that got
> issued.
> c) Now do a scan similar to Full Table Scan till that max id. Now, while we
> are scanning the blocks, note down the right siblings in a list, if the
> right sibling block id is greater than the max id that got issued. These are
> the ones, which have got split after the scan started
> d) Now after we reach that max block, try to range scan on missing links
> till we hit the end / get a right sibling less than the max block id noted.
>
> Once we do this for all the missing links, we have scanned through the
> entire chain. So this will definitely be faster than range scan.

You also need to avoid scanning the same tuple twice. That's not a
problem for VACUUM, but it is for full index scans.

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