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* dblink_exists
@ 2020-12-21 01:35 ml@ft-c.de
0 siblings, 1 reply; 3+ messages in thread
From: ml@ft-c.de @ 2020-12-21 01:35 UTC (permalink / raw)
To: pgsql-sql@lists.postgresql.org
Hello,
I need a function like "dblink_exists()", but there is no one.
Here is my script:
create function trading.stats_symbols() returns boolean as
$$
declare
sql text;
begin
sql='...';
truncate trading.stats_symbols ;
perform dblink_connect('updatesymbols', 'dbname=ftc') ;
perform dblink_send_query('updatesymbols', sql) ;
perform dblink_disconnect('updatesymbols') ;
end;
$$ language plpgsql;
My general problem:
I need a command that send a answer immediately and not, when the query
if finished.
dblink_send_query connect with the own database and runs a long time.
When someone start the script again (when it is running), so I need a
section like:
if dblink_exists(updatesymbols) -- but this function do not exists
then
return false -- or do nothing
end if;
dblink_is_busy is not usable: when the function is not running, it
stops.
2. question:
When dlink_send_query is running,
select dblink_get_connections()
send NULL as answer.
Franz
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: dblink_exists
@ 2020-12-21 01:52 David G. Johnston <david.g.johnston@gmail.com>
parent: ml@ft-c.de
0 siblings, 1 reply; 3+ messages in thread
From: David G. Johnston @ 2020-12-21 01:52 UTC (permalink / raw)
To: ml@ft-c.de <ml@ft-c.de>; +Cc: pgsql-sql@lists.postgresql.org <pgsql-sql@lists.postgresql.org>
On Sunday, December 20, 2020, <ml@ft-c.de> wrote:
>
> My general problem:
> I need a command that send a answer immediately and not, when the query
> if finished.
>
dblink_exec()?
>
> When someone start the script again (when it is running), so I need a
> section like:
Advisory locks?
>
> 2. question:
> When dlink_send_query is running,
> select dblink_get_connections()
> send NULL as answer.
>
>
Don’t know - though suggest showing actual code that results in this
behavior.
David J.
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: dblink_exists
@ 2020-12-21 05:07 ml@ft-c.de
parent: David G. Johnston <david.g.johnston@gmail.com>
0 siblings, 0 replies; 3+ messages in thread
From: ml@ft-c.de @ 2020-12-21 05:07 UTC (permalink / raw)
To: pgsql-sql@lists.postgresql.org
On Sun, 2020-12-20 at 18:52 -0700, David G. Johnston wrote:
> On Sunday, December 20, 2020, <ml@ft-c.de> wrote:
> >
> > My general problem:
> > I need a command that send a answer immediately and not, when the
> > query
> > if finished.
> dblink_exec()?
no, it needs a connection string
>
> >
> > When someone start the script again (when it is running), so I need
> > a
> > section like:
> Advisory locks?
lock on a table: it is the best solution
> >
> > 2. question:
> > When dlink_send_query is running,
> > select dblink_get_connections()
> > send NULL as answer.
> >
> Don’t know - though suggest showing actual code that results in this
> behavior.
Franz
^ permalink raw reply [nested|flat] 3+ messages in thread
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2020-12-21 01:35 dblink_exists ml@ft-c.de
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