distinct on get_all()/between()

[nviennot]

r.between(:index => :some_index).distinct does not work. RethinkDB complains that the id index and the some_index index are both being used. However, get_all() works fine. Example:

#!/usr/bin/env ruby
require 'rethinkdb'
include RethinkDB::Shortcuts

r.connect(:host => 'localhost', :port => 28015, :db => :test).repl
r.db_drop(:test).run rescue nil
r.db_create(:test).run
r.table_create(:table).run

r.table(:table).index_create(:field1).run

# returns 0
puts r.table(:table).get_all(1,3, :index => :field1).distinct.count.run

# raises Cannot use 2 indexes in the same operation. Trying to use field1 and id (RethinkDB::RqlRuntimeError)
puts r.table(:table).between(1,3, :index => :field1).distinct.count.run

[danielmewes]

That seems to be a bug, sorry you ran into it.

Pinging @mlucy

[mlucy]

This is indeed a bug. A fix is in CR 2321 by @danielmewes .

[nviennot]

How do I retrieve the server version?
I need to know the server version so that I can apply a coerce_to('array') as a workaround on the buggy between() to allow distinct() to work.
Can we have something similar to http://redis.io/commands/info ? but maybe with some sort of fake table or something, whatever makes sense for you?

[danielmewes]

You'll be able to get the server version from a "pseudo table" starting with RethinkDB 1.16 (it will be in r.db('rethinkdb').table('server_status')).
Right now it's not available through ReQL unfortunately.

As long as the between/get_all are run on a multi-index, always adding the coerce_to('array') is probably fine. distinct() is going to do the same thing internally anyway in those cases.

[mlucy]

This is in next and v1.15.x. (@danielmewes, despite what I told you in person a second ago, the changes in next were almost exactly analagous to the changes in 1.15.x, it just didn't look like it at first because one of the types had changed so the merge conflict looked much messier than it actually was.)

[AtnNn]

@nviennot A fix has been released in RethinkDB 1.15.3

[nviennot]

nice 👍