Execute marks end of transaction?

[Jimmy Li]

Can I end a transaction as soon as I call execute()? or do I have to wait
until I finish fetching all the rows?

For example, I have:

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   $dbh->do("start transaction");

   my $groups_query = $dbh->prepare(qq{select id, name from staff_grp});
   $groups_query->execute;

# place1

   while (my @one_group = $groups_query->fetchrow_array)
   {
       print @one_group;
   }

#place 2

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Can I end the transaction in #place1 or do I have to wait until #place2?