Re: Custom Scan APIs (Re: Custom Plan node)

Stephen Frost <sfrost@snowman.net> writes:
> * Ashutosh Bapat (ashutosh.bapat@enterprisedb.com) wrote:
>> During EXPLAIN, ExecInitNode() is called. If ExecInitNode() fires queries
>> to foreign servers, those would be fired while EXPLAINing a query as well.
>> We want to avoid that. Instead, we can run EXPLAIN on that query at foreign
>> server. But again, not all foreign servers would be able to EXPLAIN the
>> query e.g. file_fdw. OR totally avoid firing query during ExecInitNode(),
>> if it's for EXPLAIN (except for ANALYSE may be).

> Agreed that we wouldn't want to actually run a query when it's just
> being explain'd.  If the FDW can't tell the difference then we'd need to
> address that, of course.

EXEC_FLAG_EXPLAIN_ONLY ...
        regards, tom lane