Here is the wordpress core function named : get_post_field($dbcolumn,$postid);is used to get the value from the database, without the loop.
get_post_field( $field, $post_id, $context ); $field = Database column name $post_id = Post id $context (optional)=Possible context values are: 'raw', 'edit', 'db', 'display', 'attribute' and 'js'.
You can use it in anywhere in the wordpress core file.Suppose your page id = 12, and you need the post content of the page id then
Now you can also get any database column value.
Sometime we need to print the any other page title and it’s excerpt content then we use the wordpress query loop so our website becomes delay i.e speedup problem . So we should to use it in file where needed and improve the website speed.
Let me know if need any help or suggestion .