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POA single query with many joins in one API request, or a few queries with some joins in separate API requests?
 

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  1. POA single query with many joins in one API request, or a few queries with some joins in separate API requests?
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    <p>What is best practice, what delivers the best performance?</p> <p>I currently have a query with many <code>LEFT JOIN</code>s that fetches a <code>user</code> and all his data, like friends, friend requests, and so on:</p> <pre><code>SELECT `user`.`id` AS `user_id`, `user`.`name` AS `user_name`, `manager`.`id` AS `manager_id`, `competition`.`id` AS `manager_competition_id`, `competition`.`name` AS `manager_competition_name`, `competition`.`week` AS `manager_competition_week`, `country`.`id` AS `manager_competition_country_id`, `country`.`name` AS `manager_competition_country_name`, `club_template`.`id` AS `manager_club_template_id`, `club_template`.`name` AS `manager_club_template_name`, `club`.`id` AS `manager_club_id`, `club`.`name` AS `manager_club_name`, `club`.`ready` AS `manager_club_ready`, `friend`.`friend_id` AS `friend_id`, `friend_user`.`name` AS `friend_name` FROM `users` AS `user` LEFT JOIN `managers` AS `manager` ON `manager`.`user_id` = `user`.`id` LEFT JOIN `competitions` AS `competition` ON `competition`.`id` = `manager`.`competition_id` LEFT JOIN `countries` AS `country` ON `country`.`id` = `competition`.`country_id` LEFT JOIN `club_templates` AS `club_template` ON `club_template`.`id` = `manager`.`club_template_id` LEFT JOIN `clubs` AS `club` ON `club`.`id` = `manager`.`club_id` LEFT JOIN `friends` AS `friend` ON `friend`.`user_id` = `user`.`id` LEFT JOIN `users` AS `friend_user` ON `friend_user`.`id` = `friend`.`friend_id` WHERE `user`.`id` = 1 </code></pre> <p>As you can see, it's a very big query. My reasoning behind this was that it's better to have just one query that can be done in one API request, like this...</p> <pre><code>/api/users/1 </code></pre> <p>...versus a few queries, each in their own API request, like this...</p> <pre><code>/api/users/1 /api/users/1/friends /api/users/1/friend_requests /api/users/1/managers </code></pre> <p>But now I'm worried, that since it's become such a huge query that it will actually hurt performance more than to split it up in separate API requests.</p> <p>What will scale better?</p> <p><strong>Update</strong></p> <p>I've changed the query to the full query. This is not the final query; I plan to add even more joins (or not, depends on the answer).</p> <p>Each table has a <code>PRIMARY KEY</code> on <code>id</code>. All association columns (<code>competition_id</code>, <code>club_id</code>, and so on) have a regular <code>INDEX</code>. The database engine is InnoDB.</p>
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      1. USBasti
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    1. COIt would be helpful if you could provide some information behind the database structure and keys, as well as the full query
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      1. POA single query with many joins in one API request, or a few queries with some joins in separate API requests?
      1. USSimon at mso.net
    2. CODone. Let me know if you need more
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