Re: Execution Plan

On Wed, 2007-01-03 at 19:44 +0000, alfranio correia junior wrote:

> I have some questions on execution plans.
> 
> When are the following plans used ?
> 
> nodeFunctionscan.c 

When there is a Set Returning Function emitting tuples.

>   nodeTidscan.c

When there is a query that accesses data using a direct TID, 
e.g. WHERE ctid = '(5,12)'

this is most frequently found in calls made through the ODBC driver when
it uses its client-side implementation of updateable cursors. This is
only used these days when we have a multi-statement request, so is
mostly unused now.

> In particular, is the plan nodeBitmapHeapscan.c always used along with 
> the nodeBitmapIndexscan.c ?

Yes

> Please, let me know if there is a previous thread on this subject or any 
> document available.

Try src/backend/executor readme and code comments, plus the main docs
are reasonable. Documentation always welcome.

--  Simon Riggs              EnterpriseDB   http://www.enterprisedb.com