dinesh salve <cooltodin...@gmail.com> writes: Hi,
> > I am working on a feature in postgres_fdw extension to show plans used > by remote postgresql servers in the output of the EXPLAIN command. > > I think this will help end users understand query execution plans used > by remote servers. Sample output for table people where people_1 is > local partition and people_2 is remote partition would look like This looks nice! Especially for the people who want a FDW based sharding cluster. > I would like community inputs on below high level thoughts: > > 1. To enable this feature, either we can introduce a new option in > EXPLAIN command e.g. (fetch_remote_plans true) or control this > behaviour using a guc defined in postgres_fdw extension. I am more > inclined towards guc as this feature is for extension > postgres_fdw. Adding the EXPLAIN command option might force other FDW > extensions to handle this. +1. > 2. For ANALYZE = false, the idea is that postgres_fdw would create a > connection to a remote server, prepare SQL to send over connection and > store received plans in ExplainState. > 3. For ANALYZE = true, idea is that postgres_fdw would set a new guc > over connection to remote server, remote server postgres_fdw would > read this guc and send back used query plan as a NOTICE (similar to > auto_explain extension does) with custom header which postgres_fdw > extension understands. We also have an opportunity to introduce a new > message type in the protocol to send back explain plans but it might > look like too much work for this feature. Open to ideas here. This generally looks good to me. Looking forward a patch for the details. -- Best Regards Andy Fan
