Hi,
I have come to conclusion that Active Record cannot stream, or enumerate
over rows; this I base on the contract with Connection Adapters that
always
return arrays of hashes – all rows from the query (with regards to
:limit
and other similar options). In other words I didn’t find any way for
Connection Adapter to return an Enumerable (or similar) that fetches the
next row from the database on demand – in fact streaming the results of
a
query.
I understand that there is support for batch in ActiveRecord::Batches
but
that is not the same as on demand streaming of results. Interesting work
on
this has been done for PostgreSQL in
GitHub - dark-panda/activerecord-postgresql-cursors: Provides some support for PostgreSQL cursors in ActiveRecord..
Are there any plans for more general inclusion of cursors / streaming
results in Active Record? Can anyone suggest an alternative?
thanks,
Zoran