I would some help in optimizing this wordpress query, it currently takes 100% cpu usage and have never got the chance for it to finish:
SELECT wp_posts.* FROM wp_posts INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id)
INNER JOIN wp_postmeta AS mt1 ON (wp_posts.ID = mt1.post_id)
INNER JOIN wp_postmeta AS mt2 ON (wp_posts.ID = mt2.post_id)
INNER JOIN wp_postmeta AS mt3 ON (wp_posts.ID = mt3.post_id)
INNER JOIN wp_postmeta AS mt4 ON (wp_posts.ID = mt4.post_id)
INNER JOIN wp_postmeta AS mt5 ON (wp_posts.ID = mt5.post_id)
INNER JOIN wp_postmeta AS mt6 ON (wp_posts.ID = mt6.post_id)
INNER JOIN wp_postmeta AS mt7 ON (wp_posts.ID = mt7.post_id)
INNER JOIN wp_postmeta AS mt8 ON (wp_posts.ID = mt8.post_id)
INNER JOIN wp_postmeta AS mt9 ON (wp_posts.ID = mt9.post_id)
INNER JOIN wp_postmeta AS mt10 ON (wp_posts.ID = mt10.post_id) WHERE 1=1 AND wp_posts.post_type = 'produkter' AND (wp_posts.post_status = 'publish' OR wp_posts.post_status = 'private') AND (wp_postmeta.meta_key = 'csv_product_month_sub'
OR (mt1.meta_key = 'csv_product_type' AND CAST(mt1.meta_value AS CHAR) = 'Mobilt Bredbaand')
OR (mt2.meta_key = 'csv_product_consumption' AND CAST(mt2.meta_value AS SIGNED) BETWEEN '0' AND '2')
OR (mt3.meta_key = 'csv_product_consumption' AND CAST(mt3.meta_value AS SIGNED) BETWEEN '3' AND '9')
OR (mt4.meta_key = 'csv_product_consumption' AND CAST(mt4.meta_value AS SIGNED) BETWEEN '10' AND '19')
OR (mt5.meta_key = 'csv_product_download' AND CAST(mt5.meta_value AS SIGNED) BETWEEN '2' AND '9')
OR (mt6.meta_key = 'csv_product_download' AND CAST(mt6.meta_value AS SIGNED) BETWEEN '10' AND '19')
OR (mt7.meta_key = 'csv_product_download' AND CAST(mt7.meta_value AS SIGNED) BETWEEN '20' AND '29')
OR (mt8.meta_key = 'csv_product_month_sub' AND CAST(mt8.meta_value AS SIGNED) BETWEEN '0' AND '49')
OR (mt9.meta_key = 'csv_product_month_sub' AND CAST(mt9.meta_value AS SIGNED) BETWEEN '50' AND '99')
OR (mt10.meta_key = 'csv_product_month_sub' AND CAST(mt10.meta_value AS SIGNED) BETWEEN '100' AND '149') ) GROUP BY wp_posts.ID ORDER BY wp_postmeta.meta_value+0 ASC
So far I have:
SELECT wp_posts.* FROM wp_posts INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id)
WHERE ID IN (
SELECT post_id from wp_postmeta
WHERE
(
(meta_key = 'csv_product_consumption' AND CAST(meta_value AS SIGNED) BETWEEN 0 AND 2)
OR (meta_key = 'csv_product_consumption' AND CAST(meta_value AS SIGNED) BETWEEN 3 AND 9)
OR (meta_key = 'csv_product_consumption' AND CAST(meta_value AS SIGNED) BETWEEN 10 AND 19)
OR (meta_key = 'csv_product_download' AND CAST(meta_value AS SIGNED) BETWEEN 2 AND 9)
OR (meta_key = 'csv_product_download' AND CAST(meta_value AS SIGNED) BETWEEN 10 AND 19)
OR (meta_key = 'csv_product_download' AND CAST(meta_value AS SIGNED) BETWEEN 20 AND 29)
OR (meta_key = 'csv_product_month_sub' AND CAST(meta_value AS SIGNED) BETWEEN 0 AND 49)
OR (meta_key = 'csv_product_month_sub' AND CAST(meta_value AS SIGNED) BETWEEN 50 AND 99)
OR (meta_key = 'csv_product_month_sub' AND CAST(meta_value AS SIGNED) BETWEEN 100 AND 149)
)
GROUP BY post_id
)
AND wp_posts.post_type = 'produkter'
AND (wp_posts.post_status = 'publish' OR wp_posts.post_status = 'private')
AND ( (wp_postmeta.meta_key = 'csv_product_type') AND (wp_postmeta.meta_value = 'Mobilt Bredbaand'))
ORDER BY wp_postmeta.meta_value+0 ASC
It no longer uses too much cpu and the query takes 0.0331 sec.
Any other ideas would be appreciated.
I came across this problem and realized the issue was with all the INNER JOINS generated by WordPress. I got the raw query from WordPress:
SELECT wp_posts.* FROM wp_posts
INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id)
INNER JOIN wp_postmeta AS mt1 ON (wp_posts.ID = mt1.post_id)
INNER JOIN wp_postmeta AS mt2 ON (wp_posts.ID = mt2.post_id)
INNER JOIN wp_postmeta AS mt3 ON (wp_posts.ID = mt3.post_id)
INNER JOIN wp_postmeta AS mt4 ON (wp_posts.ID = mt4.post_id)
INNER JOIN wp_postmeta AS mt5 ON (wp_posts.ID = mt5.post_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (7,11,12,13,14,15) AND wp_posts.ID NOT IN (
SELECT object_id
FROM wp_term_relationships
WHERE term_taxonomy_id IN (10)
) ) AND wp_posts.post_type IN ('post', 'page', 'attachment', 'product', 'store_page') AND (wp_posts.post_status = 'publish') AND ( (wp_postmeta.meta_key = 'product_type' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (mt1.meta_key = 'product_type2' AND CAST(mt1.meta_value AS CHAR) = 'type_pre_ground')
OR (mt2.meta_key = 'product_type3' AND CAST(mt2.meta_value AS CHAR) = 'type_pre_ground')
OR (mt3.meta_key = 'product_type4' AND CAST(mt3.meta_value AS CHAR) = 'type_pre_ground')
OR (mt4.meta_key = 'product_type5' AND CAST(mt4.meta_value AS CHAR) = 'type_pre_ground')
OR (mt5.meta_key = 'product_type6' AND CAST(mt5.meta_value AS CHAR) = 'type_pre_ground') ) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC
This never completed and tied up the CPU at a very high load. I removed the last two INNER JOINs (and corresponding WHERE clauses) and got results in 2 seconds:
SELECT wp_posts.* FROM wp_posts
INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id)
INNER JOIN wp_postmeta AS mt1 ON (wp_posts.ID = mt1.post_id)
INNER JOIN wp_postmeta AS mt2 ON (wp_posts.ID = mt2.post_id)
INNER JOIN wp_postmeta AS mt3 ON (wp_posts.ID = mt3.post_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (7,11,12,13,14,15) AND wp_posts.ID NOT IN (
SELECT object_id
FROM wp_term_relationships
WHERE term_taxonomy_id IN (10)
) ) AND wp_posts.post_type IN ('post', 'page', 'attachment', 'product', 'store_page') AND (wp_posts.post_status = 'publish') AND ( (wp_postmeta.meta_key = 'product_type' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (mt1.meta_key = 'product_type2' AND CAST(mt1.meta_value AS CHAR) = 'type_pre_ground')
OR (mt2.meta_key = 'product_type3' AND CAST(mt2.meta_value AS CHAR) = 'type_pre_ground')
OR (mt3.meta_key = 'product_type4' AND CAST(mt3.meta_value AS CHAR) = 'type_pre_ground') ) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC
So I realized that removing the INNER JOINS was the key to speeding up the query. I re-wrote the query with only one wp_postmeta INNER JOIN and got results in fractions of a second:
SELECT wp_posts.* FROM wp_posts
INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id)
INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (7,11,12,13,14,15) AND wp_posts.ID NOT IN (
SELECT object_id
FROM wp_term_relationships
WHERE term_taxonomy_id IN (10)
) )
AND wp_posts.post_type IN ('post', 'page', 'attachment', 'product', 'store_page')
AND (wp_posts.post_status = 'publish')
AND ( (wp_postmeta.meta_key = 'product_type' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (wp_postmeta.meta_key = 'product_type2' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (wp_postmeta.meta_key = 'product_type3' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (wp_postmeta.meta_key = 'product_type4' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (wp_postmeta.meta_key = 'product_type5' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground')
OR (wp_postmeta.meta_key = 'product_type6' AND CAST(wp_postmeta.meta_value AS CHAR) = 'type_pre_ground') )
GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC
With this solution I created a WordPress filter to convert the postmeta query to the faster format:
function custom_get_meta_sql( $meta_sql )
{
global $wpdb;
$posts_table = $wpdb->prefix . 'posts';
$postmeta_table = $wpdb->prefix . 'postmeta';
//use single INNER JOIN
$meta_sql['join'] = " INNER JOIN {$postmeta_table} AS pmta ON ({$posts_table}.ID = pmta.post_id) ";
//replace the mtNN aliases with wp_postmeta
$where_clause = $meta_sql['where'];
$where_clause = str_replace("{$postmeta_table}.", 'pmta.', $where_clause);
$where_clause = preg_replace('/mt\d+\.meta_/i', 'pmta.meta_', $where_clause);
$meta_sql['where'] = $where_clause;
return $meta_sql;
}
add_filter( 'get_meta_sql', 'custom_get_meta_sql' );
This filter should be located in the functions.php file of your WordPress Theme.
This is an old post now, but you might consider trying Horizontal Meta. Horizontal Meta monitors specific keys in the post & user meta tables and extracts them out into a relational/horizontal format. You can still use the WordPress query engine to run queries, but Horizontal Meta will rewrite the queries to speed it up. Available here: http://wordpress.org/plugins/horizontal-meta/
