On Fri, Nov 19, 2010 at 10:51 PM, Vaibhav Kaushal
<vaibhavkaushal123@gmail.com> wrote:
> Is no one ready to help on this? :(
Apparently, no one is ready to drop what they are doing to immediately
answer your email before all the other ones they need to answer, but I
wouldn't infer from that that no one wants to help. It doesn't seem
very realistic to me to expect a 12-hour turnaround on free support,
but what do I know?
With regards to your question, for each type of plan node, there is an
associated "plan state" node. This is an important distinction
because, IIUC, plans can be reused, so plan state contains the
information that might need to be reset on each run. Scan state is
just a plan state node for a scan node. I believe a tuple projection
is what you get when you do something like SELECT
generate_series(1,10) FROM tbl - the set-returning function has to be
"projected" in multiple tuples. EState I could use some hints on
myself. A qual is a filter condition, e.g. in SELECT * FROM tbl WHERE
x = 1, the "x = 1" part is a qual. It's helpful to grep src/include
for the structures in question; the information they contain often
helps to understand their purpose.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company