Re: Parallel copy - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Parallel copy
Date
Msg-id e610297e-2a3b-e71d-1b65-85cd1185f342@iki.fi
Whole thread Raw
In response to Re: Parallel copy  (vignesh C <vignesh21@gmail.com>)
Responses Re: Parallel copy
Re: Parallel copy
List pgsql-hackers
On 27/10/2020 15:36, vignesh C wrote:
> Attached v9 patches have the fixes for the above comments.

I did some testing:

/tmp/longdata.pl:
--------
#!/usr/bin/perl
#
# Generate three rows:
# foo
# longdatalongdatalongdata...
# bar
#
# The length of the middle row is given as command line arg.
#

my $bytes = $ARGV[0];

print "foo\n";
for(my $i = 0; $i < $bytes; $i+=8){
     print "longdata";
}
print "\n";
print "bar\n";
--------

postgres=# copy longdata from program 'perl /tmp/longdata.pl 100000000' 
with (parallel 2);

This gets stuck forever (or at least I didn't have the patience to wait 
it finish). Both worker processes are consuming 100% of CPU.

- Heikki



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