Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-07-01 Thread David G. Johnston
On Mon, Jun 20, 2016 at 2:54 AM, Masahiko Sawada wrote: > >> QUERY PLAN > >> > >> >

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-07-01 Thread Robert Haas
On Mon, Jun 20, 2016 at 3:06 AM, Satoshi Nagayasu wrote: > IMHO, "actual rows" of "Parallel Seq Scan" should not be divided by the loops, > because the total rows processed here is 1000, not 333 * 3. > I think the actual row value shown here "333 " is a bit confusing

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Amit Kapila
On Mon, Jun 20, 2016 at 12:47 PM, Amit Langote < langote_amit...@lab.ntt.co.jp> wrote: > > On 2016/06/20 15:42, Amit Kapila wrote: > > > >> > >> After spent time to investigate this behaviour, ISTM that the problem > >> is nloops of Parallel Seq Scan. > >> Parallel Seq Scan is done only once, but

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Amit Kapila
On Mon, Jun 20, 2016 at 12:24 PM, Masahiko Sawada wrote: > > > In following case, it look to me that no one collect the tuple. > But it's obviously incorrect, this query collects a tuple(aid = 10) actually. > > postgres(1)=# explain analyze verbose select * from

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Amit Langote
On 2016/06/20 15:42, Amit Kapila wrote: > On Mon, Jun 20, 2016 at 11:48 AM, Masahiko Sawada > wrote: >> >> Hi all, >> >> My colleague noticed that the output of EXPLAIN ANALYZE doesn't work >> fine for parallel seq scan. >> [ ... ] >> For example, the above result shows,

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Satoshi Nagayasu
Hi, 2016-06-20 15:42 GMT+09:00 Amit Kapila : > On Mon, Jun 20, 2016 at 11:48 AM, Masahiko Sawada > wrote: >> >> Hi all, >> >> My colleague noticed that the output of EXPLAIN ANALYZE doesn't work >> fine for parallel seq scan. >> >> postgres(1)=#

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Masahiko Sawada
On Mon, Jun 20, 2016 at 3:42 PM, Amit Kapila wrote: > On Mon, Jun 20, 2016 at 11:48 AM, Masahiko Sawada > wrote: >> >> Hi all, >> >> My colleague noticed that the output of EXPLAIN ANALYZE doesn't work >> fine for parallel seq scan. >> >>

Re: [HACKERS] Actuall row count of Parallel Seq Scan in EXPLAIN ANALYZE .

2016-06-20 Thread Amit Kapila
On Mon, Jun 20, 2016 at 11:48 AM, Masahiko Sawada wrote: > > Hi all, > > My colleague noticed that the output of EXPLAIN ANALYZE doesn't work > fine for parallel seq scan. > > postgres(1)=# explain analyze verbose select count(*) from pgbench_accounts ; >