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POLeft Joins are what I want but they are very slow?
 

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  1. POLeft Joins are what I want but they are very slow?
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    <p>Overview: </p> <p>I have three tables 1) subscribers, bios, and shirtsizes and i need to find the subscribers without a bio or shirtsizes </p> <p>the tables are laid out such as </p> <p><strong>subscribers</strong></p> <pre><code>| season_id | user_id | </code></pre> <p><strong>bio</strong></p> <pre><code>| bio_id | user_id | </code></pre> <p><strong>shirt sizes</strong></p> <pre><code>| bio_id | shirtsize | </code></pre> <p>And I need to find all users who do not have a bio or shirtsize, (if no bio; then no shirtsize via relation) for any given season.</p> <p>I originally wrote a query like:</p> <pre><code>SELECT * FROM subscribers s LEFT JOIN bio b ON b.user_id = subscribers.user_id LEFT JOIN shirtsizes ON shirtsize.bio_id = bio.bio_id WHERE s.season_id = 185181 AND (bio.bio_id IS NULL OR shirtsize.size IS NULL); </code></pre> <p>but it is taking 10 seconds to complete now. </p> <p>I am wondering how I can restructure the query (or possibly the problem) so that it will preform reasonably. </p> <p>Here is the mysql explain: (ogu = subscribers, b = bio, tn = shirtshize)</p> <pre><code>| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+-------+---------------+---------+---------+-------------+--------+-------------+ | 1 | SIMPLE | ogu | ref | PRIMARY | PRIMARY | 4 | const | 133 | Using where | | 1 | SIMPLE | b | index | NULL | PRIMARY | 8 | NULL | 187644 | Using index | | 1 | SIMPLE | tn | ref | nid | nid | 4 | waka2.b.nid | 1 | Using where | </code></pre> <p>The above is pretty sanitized, here's the realz info:</p> <pre><code>mysql&gt; DESCRIBE subscribers +-----------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+---------+------+-----+---------+-------+ | subscribers | int(11) | NO | PRI | | | | uid | int(11) | NO | PRI | | | mysql&gt; DESCRIBE bio; +-------+------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------------+------+-----+---------+-------+ | bio_id | int(10) unsigned | NO | PRI | 0 | | | uid | int(10) unsigned | NO | PRI | 0 | | mysql&gt; DESCRIBE shirtsize; +-------+------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------------+------+-----+---------+-------+ | bio_id | int(10) unsigned | NO | PRI | 0 | | | shirtsize | int(10) unsigned | NO | PRI | 0 | | </code></pre> <p>and the real query looks like:</p> <pre><code>SELECT ogu.nid, ogu.is_active, ogu.uid, b.nid AS bio_node, tn.nid AS size FROM og_uid ogu LEFT JOIN bio b ON b.uid = ogu.uid LEFT JOIN term_node tn ON tn.nid = b.nid WHERE ogu.nid = 185033 AND ogu.is_admin = 0 AND (b.nid IS NULL OR tn.tid IS NULL) </code></pre> <p>nid is season_id or bio_id (with a type); term_node is going to be the shirtsize </p>
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    1. USmwigdahl
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      1. POLeft Joins are what I want but they are very slow?
      1. UScodingbear
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    1. CODo those tables have any indexes?
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      1. USMitch Wheat
    2. CO@jskulksi: Can we ask you to include "SHOW CREATE TABLE" output for each table?
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      1. POLeft Joins are what I want but they are very slow?
      1. USBill Karwin
 

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