On Sat, Mar 9, 2024 at 4:10 PM Adrian Klaver <adrian.klaver@xxxxxxxxxxx> 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.vass@xxxxxxxxx
> <mailto:hector.vass@xxxxxxxxx>> wrote:
>
>
>
> On Sat, Mar 9, 2024 at 3:02 PM kuldeep singh
> <kuldeeparora89@xxxxxxxxx <mailto:kuldeeparora89@xxxxxxxxx>> 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.klaver@xxxxxxxxxxx
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'' ';
