我正在使用合著者插件：

https://wordpress.org/plugins/co-authors-plus/

我编写了一些SQL，以便在搜索帖子时从显示名称与搜索查询匹配的作者那里获取帖子。它实际上是在一个非常小的测试博客上工作，但它在一个生产博客上花费了很长时间（实际上很长，以至于我们的主机抛出502）。

这项工作只有一部分我不了解，那就是编写SQL查询来实现我想要的：

“author”是来自coauthors插件的自定义分类法（请参见上面的链接）

这是我的SQL。我能做些什么来提高性能吗？

http://pastebin.com/TZA7tqCv

<?php

    /**
     * Create an SQL statement for searching posts by coauthor name.
     *
     * @todo I\'m having trouble getting $wpdb -> prepare to work, although I don\'t think it\'s necessary since I am sanitizing the data very strictly.
     * @todo I really have no idea if this is actually how you do a JOIN.
     *
     * @param string $s The search term.
     * @param string $matching_users A comma-sep list of user ID\'s.
     * @param int $limit The maximum number of results.
     * @param int $offset The number of results to skip, as per pagination.
     * @return string SQL for searching posts by coauthor name.
     */
    private function sql( $s, $matching_users, $limit, $offset ) {

            // Sanitize the search term and matching users, although replacing illegal chars with a wildcard.
            $s              = $this -> sanitize( $s, \'_\' );
            $matching_users = $this -> sanitize( $matching_users, \'_\' );

            // And then hit them with esc_sql because I\'m paranoid.
            $s              = esc_sql( $s );
            $matching_users = esc_sql( $matching_users );

            // Sanitize the LIMIT making sure it\'s an int, defaulting to 10.
            $limit = absint( $limit );
            if( empty ( $limit ) ) { $limit = 10; }

            // Sanitize the the OFFSET, making sure it\'s an int, defaulting to 0.
            $offset = absint( $offset );
            if( empty ( $offset ) ) { $offset = 0; }

            // We\'re gonna need this to build our table names.
            global $wpdb;

            // Shorten the name of the psots table for easier reading.
            $p  = $wpdb -> posts;
            $tt = $wpdb -> term_taxonomy;
            $tr = $wpdb -> term_relationships;
            $t  = $wpdb -> terms;

            $sql = <<<SQL

                    /* We\'re selecting posts in order to fulfill the search query. */
                    SELECT

                    /* This will prevent multiple copies of the same post, though I don\'t totally understand why we\'d otherwise be getting them. */
                    DISTINCT

                    /* Populates a value so you can determine how many rows you would have gotten without the LIMIT clause. */
                    SQL_CALC_FOUND_ROWS

                    /* We want every column from the posts table. */
                    $p.*

                    /* I want results from the posts table, but I have to invoke these other tables for when I am sort of using them later in WHERE clause.  */
                    FROM $p, $tr, $t, $tt

                    WHERE (

                        /* See if the search term matches the post title. */
                        (
                            $p.post_title LIKE \'%$s%\'

                        /* See if the search term matches the post content. */
                        ) OR (
                            $p.post_content LIKE \'%$s%\'

                        /* See if the post author is in the array of author ID\'s that I have from my script. */
                        ) OR (
                            $p.post_author IN ( $matching_users )

                        /* This is the part where I\'m hazy. */
                        ) OR (

                            /* Search the TT table for terms from the \'author\' taxonomy ...  */
                            (
                                $tt.taxonomy = \'author\'

                            /* ... and whose term description matches the search term ...  */
                            ) AND (
                                $tt.description LIKE \'%$s%\'

                            /* ... and whose ID matches the ID in the terms table where ...  */
                            ) AND (
                                $tt.term_id = $t.term_id

                            /* ... the term_id matches the TR table where ...  */
                            ) AND (
                                $tr.term_taxonomy_id = $t.term_id

                            /* ... the object_id in the TR table matches the post ID ... */
                            ) AND (
                                $tr.object_id = $p.ID
                            )

                        /* End the part where I\'m hazy. */
                        )

                    /* Limit results to the normal post types. */
                    ) AND $p.post_type IN (
                        \'post\', \'page\'

                    /* Limit results to the normal post status. */
                    ) AND (
                        $p.post_status = \'publish\'

                    /* WP Core does this and I have no idea why. */
                    ) AND (
                            1 = 1
                    )

                    /* Get results in reverse cron, like usual. */
                    ORDER BY $p.post_date DESC

                    /* Of course we only want our normal posts per page. */
                    LIMIT $limit

                    /* And we need to account for pagination. */
                    OFFSET $offset

SQL;

            return $sql;
    }