Re: Postgresql UPDATE LOCKS unrelated rows.

Hi Stephan,

Here is the table structure.  FYI, we tried the experiment with mysql
and the concurrency is working fine.

create table TABLE1( TABLE_ID IDENTITY NOT NULL ,
                        VA_ID SMALLINT NOT NULL,

                        V_STATES_ID SMALLINT NOT
NULL,
                        V_VOL VARCHAR(6),
                        V_OBJ_ID INT,
                        V_CELL SMALLINT,
                        V_POOL VARCHAR(255),
                    FOREIGN KEY(VA_ID) REFERENCES
TABLE2(VA_ID) ON DELETE CASCADE,
                    FOREIGN KEY(V_STATES_ID)
REFERENCES V_STATES(V_STATES_ID),
                    PRIMARY KEY(TABLE_ID));
We were trying to update V_VOL using following statement:

UPDATE TABLE1 SET V_VOL = 'ABCD' WHERE TABLE_ID = 100000

Regards,
Ravi

-----Original Message-----
From: Stephan Szabo [mailto:sszabo@megazone.bigpanda.com]
Sent: Thursday, September 18, 2003 8:32 PM
To: Ravi T Ramachandra
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] Postgresql UPDATE LOCKS unrelated rows.



On Thu, 18 Sep 2003, Ravi T Ramachandra wrote:

>
> Hi,
>
> We are using postgresql 7.3.2 on lunux platform.   We performed
locking
> test as follows via JDBC:
>
> Started 2 concurrent transaction with autocommit false and isolation
> READ_COMMITTED :
>
> Transaction 1:
> ===========
> Update row 1
> Sleep for 30 seconds
> commit:
>
> Transaction 2:
> ===========
> Updated row 10000
> commit
>
> The second update had to wait for the first update operation to
> finish. We also made sure that the 2 unrelated rows are not on the
> same page.
>
> Is this expected behavior ?
> Does update lock the whole table ?

Generally not, but you really haven't given alot of information.  What
is the table layout for the table in question?  Are there foreign keys
involved?


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