Hi!
I have a problem with ACCESS EXCLUSIVE lock when I drop a reference in
transaction. I have 2 tables:
create table a(id SERIAL primary key);
create table b(id SERIAL primary key references a(id));
After that I have 2 processes: P1, P2
In P1:
begin;
ALTER TABLE b DROP CONSTRAINT b_id_fke
Scott Marlowe wrote:
What if, a minute or two after the drop contraint, you issue a rollback?
After the DROP CONSTRAINT I insert 4 million rekords into the TABLE b.
After the inserts I remake the dropped constraints, and commit the
transaction (P1). This solution is faster then the conventio
Tom Lane wrote:
This isn't going to be changed, because the likely direction of future
development is that the planner will start making use of constraints
even for SELECT queries. This means that a DROP CONSTRAINT operation
could invalidate the plan of a SELECT query, so the locking will be
ess
Hi,
You should try the next queries:
select support_person_id from ticket_crm_map where crm_id = 7 GROUP BY
support_person_id;
select support_person_id from ticket_crm_map where crm_id = 1 GROUP BY
support_person_id;
It can use the 'ticket_crm_map_crm_id_suppid' index.
Generally the Postgres u
Hi,
You can try some variation:
SELECT
book_id
FROM
bookgenres, genre_children
WHERE
bookgenres.genre_id = genre_children.genre_child_id AND
genre_children.genre_id = 1
GROUP BY book_id
LIMIT 10
The next works if the 'genre_child_id' is UNIQUE on the 'genre_children'
table.
SELEC
