Path: | doc/release_notes/4.10.0.txt |
Last Update: | Fri Oct 06 03:25:22 +0000 2017 |
Combining these three optimizations, here are the performance increases compared to 4.9.0 for a couple example datasets:
ds1 = DB[:a] ds2 = DB[:a].select(:a, :b).where(:c=>1).order(:d, :e) .sql .all (1 row) ds1 140% 11% ds2 187% 32%
On some databases, execution time of UNION queries with n subqueries increases faster than O(n). Also, there are limits on the number of subqueries supported in a single UNION query. Sequel chooses a default limit of 40 subqueries per UNION query. You can increase this via the :subqueries_per_union association option.
Filtering by limited associations using a correlated subquery strategy does not work in all cases, but it should handle most cases correctly.
DB.call_mssql_sproc(:sproc_name, :args => { 'input_arg1_name' => 'input arg1 value', 'input_arg2_name' => 'input arg2 value', 'output_arg_name' => [:output, 'int', 'result key name'] })