Hi all,
I have a problem that I just can't seem to solve:
I want to divide the count of one table by the count of another -
seems simple enough!
I created simple VIEWs with counts of the tables, but I just can't
grasp the logic!
DDL and DML (simplified) at the bottom of post.
I tried various combinations of things like basic SELECTs.
SELECT avg FROM ((SELECT cnt1 FROM v1)/(SELECT cnt2 FROM v2));
and I also tried to use CTEs as follows:
WITH num AS
(
SELECT cnt1 FROM v1
),
div AS
(
SELECT cnt2 FROM v2
)
SELECT (num.cnt1/div.cnt2);
Should you require any further information or if this should be on
another list, please don't hesitate to contact me and/or let me know.
I would appreciate a short explanation of where I'm going wrong also.
TIA and rgs,
================== DDL and DML
CREATE TABLE t1 (x INT);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (4);
CREATE VIEW v1 AS (SELECT COUNT(*) AS cnt1 FROM t1);
CREATE TABLE t2 (y INT);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
INSERT INTO t2 VALUES (5);
CREATE VIEW v2 AS (SELECT COUNT(*) AS cnt1 FROM t2);
2018-05-29 7:47 GMT+01:00 Thomas Kellerer <spam_eater@gmx.net>:
> Andres Freund schrieb am 29.05.2018 um 08:28:
>>> But neither the Linux binaries nor the Windows binaries were compiled with the --with-llvm option
>>> (will JITting be possible with Windows at all?)
>>
>> Not in 11.
>
> I assumed that ;)
> Not a real problem.
>
> But what about Linux binaries with JITting enabled?
> I would like to test some of our DWH queries to see if that improves performance
>
> Or do I need to compile Postgres 11 myself to get that?
>
> Thomas
>
>
>
