On 01/10/2015 01:52 PM, Jacob Carlborg wrote:
On 2015-01-10 13:36, Martin Nowak wrote:
The idea isn't bad, but the performance will suck. This is generally
known as N+1 query, only that this is even worse, as each field is
queried individually.
Since the "all" method was called I would assume all rows in the person
table are fetched in one single query. Although I don't know if that
will work if not the whole row should be loaded.
For row or document oriented databases you want to query all fields in
parallel. For columnar stores it might be possible to efficiently query
specific fields for many documents.
Here is a sketch for an optimal solution. I'm actually eagerly waiting
that someone finally implements it.
http://dpaste.dzfl.pl/cd375ac594cf
How would you handled fetching multiple rows and a foreach loop, i.e. my
example?
I'd simple produce multiple rows, the principle remains the same.
Perhaps a detail but using a wrapped type instead of the raw types in
Person you could handle things like null in the database.
The example already uses Variant.
