Re: Parallel Bitmap Heap Scan reports per-worker stats in EXPLAIN ANALYZE - Mailing list pgsql-hackers

From David Geier
Subject Re: Parallel Bitmap Heap Scan reports per-worker stats in EXPLAIN ANALYZE
Date
Msg-id e7fe35e4-b5b1-2c61-65d6-0af341669b77@gmail.com
Whole thread Raw
In response to Parallel Bitmap Heap Scan reports per-worker stats in EXPLAIN ANALYZE  (David Geier <geidav.pg@gmail.com>)
Responses Re: Parallel Bitmap Heap Scan reports per-worker stats in EXPLAIN ANALYZE  (Dmitry Dolgov <9erthalion6@gmail.com>)
List pgsql-hackers
Hi,

On 1/20/23 09:34, David Geier wrote:
> EXPLAIN ANALYZE for parallel Bitmap Heap Scans currently only reports 
> the number of heap blocks processed by the leader. It's missing the 
> per-worker stats. The attached patch adds that functionality in the 
> spirit of e.g. Sort or Memoize. Here is a simple test case and the 
> EXPLAIN ANALYZE output with and without the patch:

Attached is a rebased version of the patch. I would appreciate someone 
taking a look.

As background: the change doesn't come out of thin air. We repeatedly 
took wrong conclusions in our query analysis because we assumed that the 
reported block counts include the workers.

If no one objects I would also register the patch at the commit fest. 
The patch is passing cleanly on CI.

-- 
David Geier
(ServiceNow)

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