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Different Lock Behavior With Create and Drop Foreign Key - Mailing list pgsql-general

From Virendra Kumar
Subject Different Lock Behavior With Create and Drop Foreign Key
Date
Msg-id 834603375.3470346.1586482852542@mail.yahoo.com
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Responses Re: Different Lock Behavior With Create and Drop Foreign Key
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Hi Team,

Here is test case.
----
create table testx
(
    v_code character varying(32),
    client_id bigint
);
alter table testx add constraint testx_pkey primary key (v_code);

create table testy
(
    dxid bigint,
    v_code character varying(32)
);
alter table testy add constraint testy_pkey primary key (dxid);
create index on testy (v_code);

Let's begin two session, in session1 I am going begin a transaction and run select on parent table:

Session1
----
begin;
select * from testx;


On another session let's call session2, I am running create FK on second table

Session2
---
alter table testy add constraint testy_fkey foreign key (v_code) references testx(v_code); <--This works.
alter table testy drop constraint testy_fkey; <--Hangs


Regards,
Virendra Kumar

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