[Solved] Wordpress Very Slow Query

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Wordpress Very Slow Query

I have this query

SELECT DISTINCT t.*
              , tt.* 
           FROM wp_terms t  
           JOIN wp_termmeta 
             ON t.term_id = wp_termmeta.term_id 
           JOIN wp_termmeta mt1 
             ON t.term_id = mt1.term_id 
           JOIN wp_termmeta mt2 
             ON t.term_id = mt2.term_id 
           JOIN wp_term_taxonomy tt 
             ON t.term_id = tt.term_id 
          WHERE tt.taxonomy IN ('episodes') 
            AND wp_termmeta.meta_key = 'episode_number'  
            AND mt1.meta_key = 'tr_id_post' 
            AND mt1.meta_value = '7547' 
            AND mt2.meta_key = 'season_number' 
            AND mt2.meta_value = '2' 
          ORDER 
             BY wp_termmeta.meta_value+0 ASC;

I don't know how to make it faster, it takes like 1.2 sec to execute, my website loads very hard because of it.

How to optimize this SQL query?

The following recommendations will help you in your SQL tuning process.
You'll find 3 sections below:

  1. Description of the steps you can take to speed up the query.
  2. The optimal indexes for this query, which you can copy and create in your database.
  3. An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
  1. Avoid Selecting Unnecessary Columns (query line: 2): Avoid selecting all columns with the '*' wildcard, unless you intend to use them all. Selecting redundant columns may result in unnecessary performance degradation.
  2. Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
  3. Use Numeric Column Types For Numeric Values (query line: 24): Referencing a numeric value (e.g. 7547) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
  4. Use Numeric Column Types For Numeric Values (query line: 26): Referencing a numeric value (e.g. 2) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
Optimal indexes for this query:
ALTER TABLE `wp_term_taxonomy` ADD INDEX `wp_taxonomy_idx_term_id_taxonomy` (`term_id`,`taxonomy`);
ALTER TABLE `wp_termmeta` ADD INDEX `wp_termmeta_idx_meta_key_meta_value_term_id` (`meta_key`,`meta_value`,`term_id`);
ALTER TABLE `wp_terms` ADD INDEX `wp_terms_idx_term_id` (`term_id`);
The optimized query:
SELECT
        DISTINCT t.*,
        tt.* 
    FROM
        wp_terms t 
    JOIN
        wp_termmeta 
            ON t.term_id = wp_termmeta.term_id 
    JOIN
        wp_termmeta mt1 
            ON t.term_id = mt1.term_id 
    JOIN
        wp_termmeta mt2 
            ON t.term_id = mt2.term_id 
    JOIN
        wp_term_taxonomy tt 
            ON t.term_id = tt.term_id 
    WHERE
        tt.taxonomy IN (
            'episodes'
        ) 
        AND wp_termmeta.meta_key = 'episode_number' 
        AND mt1.meta_key = 'tr_id_post' 
        AND mt1.meta_value = '7547' 
        AND mt2.meta_key = 'season_number' 
        AND mt2.meta_value = '2' 
    ORDER BY
        wp_termmeta.meta_value + 0 ASC

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