Teddy Schmitz schrieb am 16.02.2017 um 05:38:
> As a quick follow up I just did an explain on the query,
>
>
> Aggregate (cost=258007258.87..258007258.88 rows=1 width=8)
> -> Nested Loop (cost=0.00..184292254.83 rows=14743000807 width=16)
> -> Seq Scan on t1 (cost=0.00..3796.41 rows=263141 w
Thanks for the link Pavel, that makes perfect sense now.
Teddy
From: David G. Johnston
Sent: Thursday, February 16, 2017 12:42:36 PM
To: Teddy Schmitz
Cc: pgsql-general@postgresql.org
Subject: [GENERAL] Problems with Greatest
On Wednesday, February 15, 2017
On Wednesday, February 15, 2017, Teddy Schmitz > wrote:
>
> select greatest(max(t1.id), max(t2.id)) from t1, t2;
>
>
I seriously doubt that the greatest function is a larger contributor to run
time than the cross join between t1 and t2.
David J.
2017-02-16 5:38 GMT+01:00 Teddy Schmitz :
> As a quick follow up I just did an explain on the query,
>
>
> Aggregate (cost=258007258.87..258007258.88 rows=1 width=8)
> -> Nested Loop (cost=0.00..184292254.83 rows=14743000807 width=16)
> -> Seq Scan on t1 (cost=0.00..3796.41 rows=263141 width=
As a quick follow up I just did an explain on the query,
Aggregate (cost=258007258.87..258007258.88 rows=1 width=8)
-> Nested Loop (cost=0.00..184292254.83 rows=14743000807 width=16)
-> Seq Scan on t1 (cost=0.00..3796.41 rows=263141 width=8)
-> Materialize (cost=0.00..1088.40 rows=56027 wi
Hello,
I have a query using Greatest that hangs and never returns when called with two
tables.
Postgres Version: 9.6
Tables
t1{ id bigint }
t2 { id bigint }
they are sharing a sequence
the query
select greatest(max(t1.id), max(t2.id)) from t1, t2;
The purpose was to call setval on t
