WordPress database error…yada yada

Everytime i bring my site up i get an error that says wordpress database error that says

WordPress database error: [Out of memory; restart server and try again (needed 4194296 bytes)]
SELECT * FROM wp_posts WHERE (post_type = ‘page’ AND post_status = ‘publish’) ORDER BY menu_order, post_title ASC

Now i tried searching this problem and couldn’t really come up with anything and the things that i did come up with did not work. Im still able to view all my posts and the pictures and videos in them but all my pages along the side and top are inaccessible…Now here comes the real problem. Im pretty much as green as green gets on these types of things. I had a friend get the domain name for me and he set up wordpress and gave me the all the FTP info and stuff, so i really still have no clue what im doing. I got the basics of FTP down and i was able to figure out how to modify my site to a certain degree and thats about it. So if anybody could explain to me fairly simple what i have to do to fix the problem, that would be great. If it makes a difference im running version 2.3.1 which i know is out of date but i have not had a chance to get around to trying to update it….So somebody please help. I really wanna get my website up and running again…