Merge branch 'user-by-login-performance' into 'master'

Improve User.by_login performance

This greatly speeds up the performance of `User.by_login`. I adopted some changes from @haynes in this patch, the credits go to him for coming up with those originally.

Fixes #2341

See merge request !1545

1 files changed, 3 insertions, 1 deletions

diff --git a/spec/benchmarks/models/user_spec.rb b/spec/benchmarks/models/user_spec.rb
index 168be20b7a5..cc5c3904193 100644
--- a/spec/benchmarks/models/user_spec.rb
+++ b/spec/benchmarks/models/user_spec.rb
@@ -11,7 +11,9 @@ describe User, benchmark: true do
       end
     end
 
-    let(:iterations) { 1000 }
+    # The iteration count is based on the query taking little over 1 ms when
+    # using PostgreSQL.
+    let(:iterations) { 900 }
 
     describe 'using a capitalized username' do
       benchmark_subject { User.by_login('Alice') }