DELETE Query Hang

DELETE Query Hang

Hi folks! 

I Have a question, in a database are a table with many files (bytea) stored
(I support this database a don't design it), but we need delete many rows
(38000 rows approx),  but I when execute query: 

BEGIN;
ALTER TABLE my_file_table DISABLE TRIGGER ALL;
DELETE FROM my_file_table WHERE id_table <> 230;

This query hang... 50 minutes and the query do not finish. 

Any suggestion? 



-----
Dame un poco de fe, eso me bastará.
Rozvo Ware Solutions 
--
Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html

Re: DELETE Query Hang

I understand, yep is a 9.5 version, Can I use query like this to execute
smaller batches?:

DELETE FROM my_table
WHERE id IN (
    SELECT id
    FROM logtable
    LIMIT 10
);

Thanks




-----
Dame un poco de fe, eso me bastará.
Rozvo Ware Solutions 
--
Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html

Re: DELETE Query Hang

> On Nov 12, 2019, at 3:47 PM, DrakoRod  wrote:
> 
> Hi folks! 
> 
> I Have a question, in a database are a table with many files (bytea) stored
> (I support this database a don't design it), but we need delete many rows
> (38000 rows approx),  but I when execute query: 
> 
> BEGIN;
> ALTER TABLE my_file_table DISABLE TRIGGER ALL;
> DELETE FROM my_file_table WHERE id_table <> 230;
> 
> This query hang... 50 minutes and the query do not finish. 
> 
> Any suggestion? 
> 
> 


You don’t mention which version you’re using be I had this trouble long ago on version 9 when deleting blobs (toast data).  You can only wait.  Or kill it and do smaller batches.

Re: DELETE Query Hang

> On Nov 12, 2019, at 4:01 PM, DrakoRod  wrote:
> 
> I understand, yep is a 9.5 version, Can I use query like this to execute
> smaller batches?:
> 
> DELETE FROM my_table
> WHERE id IN (
>    SELECT id
>    FROM logtable
>    LIMIT 10
> );
> 
> Thanks
> 

I think you still want to qualify as you had previously.. id <> 230 or something.

I’m not saying this is faster, in total, but you will get through!

> 
> 
> 
> -----
> Dame un poco de fe, eso me bastará.
> Rozvo Ware Solutions 
> --
> Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html
> 
> 

Sv: DELETE Query Hang

do $_$
declare
    num_rows bigint;
begin
    loop
        delete from YourTable where id in
                                    (select id from YourTable where id < 500 limit 100);       get diagnostics num_rows = row_count;       raise notice 'deleted % rows', num_rows;       exit when num_rows = 0;   end loop;
end;$_$;