Database tables

I am having some trouble with my database. The site seems to be functioning normally visually, but i am getting errors such as the following:

made by require, require_once, do_action, call_user_func_array, xml_sitemaps->do_robots, xml_sitemaps->generate, sitemap_xml->generate, sitemap_xml->home
[29-Dec-2010 19:54:22] WordPress database error Out of memory (Needed 8388580 bytes) for query
SELECT posts.ID,
posts.post_author,
posts.post_name,
posts.post_type,
posts.post_status,
posts.post_parent,
posts.post_date,
posts.post_modified,
CAST(posts.post_modified AS DATE) as lastmod,
CASE COUNT(DISTINCT CAST(revisions.post_date AS DATE))
WHEN 0
THEN
0
ELSE
DATEDIFF(CAST(NOW() AS DATE), CAST(posts.post_date AS DATE))
/ COUNT(DISTINCT CAST(revisions.post_date AS DATE))
END as changefreq,
CASE
WHEN posts.post_parent = 0 OR COALESCE(COUNT(DISTINCT children.ID), 0) <> 0
THEN
.4
ELSE
.8
END as priority
FROM wp_posts as posts
LEFT JOIN wp_posts as revisions
ON revisions.post_parent = posts.ID
AND revisions.post_type = ‘revision’
AND DATEDIFF(CAST(revisions.post_date AS DATE), CAST(posts.post_date AS DATE)) > 2
AND DATE_SUB(CAST(NOW() AS DATE), INTERVAL 1 YEAR) < CAST(revisions.post_date AS DATE)
LEFT JOIN wp_posts as children
ON children.post_parent = posts.ID
AND children.post_type = ‘page’
AND children.post_status = ‘publish’
LEFT JOIN wp_postmeta as redirect_url
ON redirect_url.post_id = posts.ID
AND redirect_url.meta_key = ‘_redirect_url’
LEFT JOIN wp_postmeta as widgets_exclude
ON widgets_exclude.post_id = posts.ID
AND widgets_exclude.meta_key = ‘_widgets_exclude’
LEFT JOIN wp_postmeta as widgets_exception
ON widgets_exception.post_id = posts.ID
AND widgets_exception.meta_key = ‘_widgets_exception’
WHERE posts.post_type = ‘page’
AND posts.post_status = ‘publish’
AND posts.post_password = ”
AND redirect_url.post_id IS NULL
AND ( widgets_exclude.post_id IS NULL OR widgets_exception.post_id IS NOT NULL )
AND posts.ID <> 4

GROUP BY posts.ID
ORDER BY posts.post_parent, posts.ID
made by require, require_once, do_action, call_user_func_array, xml_sitemaps->do_robots, xml_sitemaps->generate, sitemap_xml->generate, sitemap_xml->pages

And when i look at the database in Phpmyadmin is says there are no tables in the database.

Anyone know what’s going on here? or have any sort of insight that might help me out?

Thanks a ton, in advance.