Re: printing results of query to file in different times

Anyone?

2017-08-24 16:15 GMT+03:00 Mariel Cherkassky <mariel(dot)cherkassky(at)gmail(dot)com>:

> I'm trying to understand what postgresql doing in an issue that I'm
> having. Our app team wrote a function that runs with a cursor over the
> results of a query and via the utl_file func they write some columns to a
> file. I dont understand why, but postgresql write the data into the file in
> the fs in parts. I mean that it runs the query and it takes time to get
> back results and when I see that the results back postgresql write to file
> the data and then suddenly stops for X minutes. After those x minutes it
> starts again to write the data and it continues that way until its done.
> The query returns total *100* rows. I want to understand why it stops
> suddenly. There arent any locks in the database during this operation.
>
> my function looks like that :
>
> func(a,b,c...)
>
> cursor cr for
>
> select ab,c,d,e.....
>
> begin
>
> raise notice - 'starting loop time - %',timeofday();
>
> for cr_record in cr
>
> Raise notice 'print to file - '%',timeofday();
>
> utl_file.write(file,cr_record)
>
> end loop
>
> end
>
> I see the log of the running the next output :
>
> starting loop 16:00
>
> print to file : 16:03
>
> print to file : 16:03
>
> print to file : 16:07
>
> print to file : 16:07
>
> print to file : 16:07
>
> print to file : 16:010
>
> ......
>
>
>
> Can somebody explain to me this kind of behavior ? Why is it taking some
> much time to write and in different minutes after the query already been
> executed and finished ? Mybe I'm getting from the cursor only part of the
> rows ?
>
>
>