Question

If my collection has 10 records.

my $records = $collection->find;
while (my $record = $records->next){
   do something;
}

Are there ten roundtrips to the mongodb server?
If so, is there any way to limit it to one roundtrip?

Thanks.

Answer 1

It’s a single query, just like querying a RDBMS.

As per the documentation:

  my $cursor = $collection->find({ i => { '$gt' => 42 } });

Executes the given $query and returns a MongoDB::Cursor with the results

  my $cursor = $collection->query({ }, { limit => 10, skip => 10 });

Valid query attributes are:

• limit – Limit the number of results.
• skip -Skip a number of results.
• sort_by – Order results.