Defect #26691
Updated by Toshi MARUYAMA over 6 years ago
Rails 4.2.7.1 20000 issues in the database When rendering the GanttsController.show action, it will issue a lot of queries to get the the start_date and due_date of an project like: <pre><code class="sql"> SELECT MIN(`issues`.`start_date`) FROM `issues` WHERE `issues`.`project_id` = ? [["project_id", 1436]] SELECT MAX(`issues`.`due_date`) FROM `issues` WHERE `issues`.`project_id` = ? [["project_id", 1436]] SELECT MIN(`issues`.`start_date`) FROM `issues` WHERE `issues`.`project_id` = ? [["project_id", 1317]] SELECT MAX(`issues`.`due_date`) FROM `issues` WHERE `issues`.`project_id` = ? [["project_id", 1317]] </code></pre> .... Which will make the performance very bad. My solution is that add cached_due_date and cached_start_date for projects.rb, and while constructing the project_tree, I will use a group query to retrieve the corresponding start_date and due_date for a group of projects, so that they don't need to issue N queries later on.