On 2020-Mar-18, Justin Pryzby wrote:
> On Sun, Mar 15, 2020 at 12:49:33PM +0100, Julien Rouhaud wrote:
> template1=# SET log_temp_files=0; explain analyze SELECT a,COUNT(1) FROM t a JOIN t b USING(a) GROUP BY 1;
> 2020-03-15 21:20:47.288 CDT [5537 5537]LOG: statement: SET log_temp_files=0;
> SET
> 2020-03-15 21:20:47.289 CDT [5537 5537]LOG: statement: explain analyze SELECT a,COUNT(1) FROM t a JOIN t b
USING(a)GROUP BY 1;
> 2020-03-15 21:20:51.253 CDT [5627 5537]LOG: temporary file: path "base/pgsql_tmp/pgsql_tmp5627.0", size
6094848
> 2020-03-15 21:20:51.253 CDT [5627 5537]STATEMENT: explain analyze SELECT a,COUNT(1) FROM t a JOIN t b
USING(a)GROUP BY 1;
> 2020-03-15 21:20:51.254 CDT [5626 5537]LOG: temporary file: path "base/pgsql_tmp/pgsql_tmp5626.0", size
6103040
> 2020-03-15 21:20:51.254 CDT [5626 5537]STATEMENT: explain analyze SELECT a,COUNT(1) FROM t a JOIN t b
USING(a)GROUP BY 1;
> 2020-03-15 21:20:51.263 CDT [5537 5537]LOG: temporary file: path
"base/pgsql_tmp/pgsql_tmp5537.1.sharedfileset/o15of16.p0.0",size 557056
I think it's overly verbose; all non-parallel backends are going to get
their own PID twice, and I'm not sure this is going to be great to
parse. I think it would be more sensible that if the process does not
have a parent (leader), %P expands to empty.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
