[GENERAL] C++ Builder prob.
When I try to run something with PostrgreSQL (libpq) in Borland C++ Builder, it does not run and write errors like "[Linker Error] Unresolved external '_PQconnectdb' referenced from C:\PROGRAM FILES\BORLAND\CBUILDER6\PROJECTS\UNIT1.OBJ". Does anybody know how to fix it? Thanks ---(end of broadcast)--- TIP 8: explain analyze is your friend
[GENERAL] Problems with Greatest
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 the sequence after doing a bulk data load
into the database. But this query never returns. I have tried it with various
combinations,
select greatest(max(t1.id), 6) from t1; -> This returns
select greatest(max(t1.id), 6) from t1, t2; -> This never returns.
The query does work if there is only a few hundred items between the tables but
I'm importing about ~300,000 rows between the two tables. I looked at
pg_stat_activity and it says the query is active
I worked around this problem using a union all query but I'm wondering if this
is a bug or I am just using greatest wrong.
Re: [GENERAL] Problems with Greatest
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 width=8)
-> Seq Scan on t2 (cost=0.00..808.27 rows=56027 width=8)
It seems it has to do a loop on 14 billion rows? Can someone explain why this
would happen?
Thanks,
Teddy
____
From: Teddy Schmitz
Sent: Thursday, February 16, 2017 12:32:41 PM
To: pgsql-general@postgresql.org
Subject: Problems with Greatest
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 the sequence after doing a bulk data load
into the database. But this query never returns. I have tried it with various
combinations,
select greatest(max(t1.id), 6) from t1; -> This returns
select greatest(max(t1.id), 6) from t1, t2; -> This never returns.
The query does work if there is only a few hundred items between the tables but
I'm importing about ~300,000 rows between the two tables. I looked at
pg_stat_activity and it says the query is active
I worked around this problem using a union all query but I'm wondering if this
is a bug or I am just using greatest wrong.
Re: [GENERAL] Problems with Greatest
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, 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.
[GENERAL] setting contrib lo visible to all schemas
hello I`m trying to restore a database that uses contrib type lo. The database uses one schema where the relations are created before restoring the schema I execute the command psql -d dbname -f path-to-contrib/lo.sql after this I restore the schema and then the data of the database the problems comes up when trying to make an update to the database schema from a delphi application the table has a column of type lo and when trying to update the table I got the error saying that lo type does not exist. I guess this is because when executing the sql command to install lo, it makes it visible from the public schema only not from the schema I`m using. So my question is how can I make lo type to be visible from all schemas by visible I mean accesible: not need to use for example public.lo to define a field of type lo thanks in advanced -- Teddy L.
Re: [GENERAL] setting contrib lo visible to all schemas
thanks tom, aparently your rigth in the sql dump file there are some set search_path changes I tried the set search_path command and use the same query that generate the error and it works on my pgadmin editor. My question is how can I set the search_path for all users or all conections so my application will find the lo type. thanks 2010/5/20 Tom Lane > Teddy Limousin writes: > > I guess this is because when executing the sql command to install lo, it > > makes it visible from the public schema only > > not from the schema I`m using. So my question is how can I make lo type > to > > be visible from all schemas > > > by visible I mean accesible: not need to use for example public.lo to > define > > a field of type lo > > It sounds like you removed the public schema from your search_path > setting. Don't do that ... > >regards, tom lane > -- Teddy Limousin
