Re: Insert with Jsonb column hangs

On Sat, Mar 9, 2024 at 4:10 PM Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

> On 3/9/24 08:00, kuldeep singh wrote:
> > Copy may not work in our scenario since we need to join data from
> > multiple tables & then convert it to json using row_to_json . This
> > json data eventually needs to be stored in a target table .
>
> Per:
>
> https://www.postgresql.org/docs/current/sql-copy.html
>
> "
> COPY { table_name [ ( column_name [, ...] ) ] | ( query ) }
>
> <...>
>
> query
>
> A SELECT, VALUES, INSERT, UPDATE, or DELETE command whose results
> are to be copied. Note that parentheses are required around the query.
>
> For INSERT, UPDATE and DELETE queries a RETURNING clause must be
> provided, and the target relation must not have a conditional rule, nor
> an ALSO rule, nor an INSTEAD rule that expands to multiple statements.
> "
>
> >
> > Will it be better if we break the process into batches of like 10,000
> > rows & insert the data in its individual transactions? Or any other
> > better solution available ?
> >
> > On Sat, Mar 9, 2024 at 9:01 PM hector vass <hector(dot)vass(at)gmail(dot)com
> > <mailto:hector(dot)vass(at)gmail(dot)com>> wrote:
> >
> >
> >
> > On Sat, Mar 9, 2024 at 3:02 PM kuldeep singh
> > <kuldeeparora89(at)gmail(dot)com <mailto:kuldeeparora89(at)gmail(dot)com>> wrote:
> >
> > Hi,
> >
> > We are inserting data close to 1M record & having a single Jsonb
> > column but query is getting stuck.
> >
> > We are using insert into select * .. , so all the operations are
> > within the DB.
> >
> > If we are running select query individually then it is returning
> > the data in 40 sec for all rows but with insert it is getting
> stuck.
> >
> > PG Version - 15.
> >
> > What could be the problem here ?
> >
> > Regards,
> > KD
> >
> >
> > insert 1M rows especially JSON that can be large, variable in size
> > and stored as blobs and indexed is not perhaps the correct way to do
> > this
> > insert performance will also depend on your tuning. Supporting
> > transactions, users or bulk processing are 3x sides of a compromise.
> > you should perhaps consider that insert is for inserting a few rows
> > into live tables ... you might be better using copy or \copy,
> > pg_dump if you are just trying to replicate a large table
> >
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com

What Adrian Klaver said ^
discovered even this works...

create view myview as (select row_to_json from mytable);

create table newtable as select * from myview where 1=0;

copy myview to program 'psql mydb postgres -c ''copy newtable from stdin'' '
;