Hi Tom
If you don't want that, you can use a WITH to lock down the result of a
single random() call.
How should I do it?
于 2012-7-25 10:55, Tom Lane 写道:
> wangqi writes:
>> ■SQL-3
>> select * from wk_mclid1 where id1= (round((random() * (10-1))::integer)
>> + 1)::integer;
>> When we excute SQ
Thanks Tom, I try it.
于 2012-7-25 10:55, Tom Lane 写道:
> wangqi writes:
>> ■SQL-3
>> select * from wk_mclid1 where id1= (round((random() * (10-1))::integer)
>> + 1)::integer;
>> When we excute SQL-3,sometimes the result was 0 record or more than 1
>> record.
>> Why?
> random() is re-evaluated for
wangqi writes:
> ¡öSQL-3
> select * from wk_mclid1 where id1= (round((random() * (10-1))::integer)
> + 1)::integer;
> When we excute SQL-3,sometimes the result was 0 record or more than 1
> record.
> Why?
random() is re-evaluated for each row scanned by the SELECT.
If you don't want that, you
Hi everyone
■SQL-1
CREATE TABLE wk_mclid1(
id1 integer ,
PRIMARY KEY(id1)
);
■SQL-2
INSERT INTO wk_mclid1(id1)
VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),(10)
GO
■SQL-3
select * from wk_mclid1 where id1= (round((random() * (10-1))::integer)
+ 1)::integer;
When we excute SQL-3,sometimes the res
Hi.
I have a 1.8TB PG database, we're doing "fairly heavy" batch updates on.
Say 2/3 of
the database monthly in a background batch process. The system is
working really
well and performing good, but we're always haunting more speed (and
smaller amount of WAL-log).
So I tried to look into how
Hello,
We are running PostgreSQL version 9.1.1 with 32GB of RAM, 32GB of SWAP and
during high load we could reach (swap + RAM) memory limit. In this case
OOM-killer kills postgresql process(es). (Out of Memory: Killed process
12345 (postgres)). As admin I would like to exclude postgresql system
pr
On 07/24/2012 08:58 AM, Gary Webster wrote:
Hello.
Thanks for the response.
There are several 'idle in transaction' on this server/app, but to a
different db/schema.
This is a cluster issue, not a database issue. So if you have an idnle
in transaction, then it is affecting your JCR schema as
Gary Webster writes:
> By "routine maintenance", do you mean autovacuum, or something else?
> Autovacuum does appear to usually get 'auto-canceled' by a lock.
That's bad and you should look into the reason why it happens. Ordinary
DML (CRUD) operations should not kick autovac off a table. If it
Hello.
Thanks for the response.
There are several 'idle in transaction' on this server/app, but to a
different db/schema.
The "repository" (JCR) schema has only a few 'idle', none 'in transaction' .
By "routine maintenance", do you mean autovacuum, or something else?
Autovacuum does appear to usu
Hello.
Thanks for the response.
Autovacuum is set VERY aggressive.
However, it does not help with the ws_bundle Toast table.
A manual _full_ vacuum (not recommended?) does do the deed.
However, it often gives this error:
ERROR: missing chunk number 0 for toast value 639113 in pg_toast_533386
BT
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