WP_Query (category)

ajax_query_attachments_args	Allows you to change the parameters passed to WP_Query during an AJAX request for media files (attachments).
post_limits	Changes the LIMIT clause of the SQL query before posts are retrieved from the database by WP_Query.
post_search_columns	Allows you to change the list of columns searched when using the `s` search parameter in WP_Query.
posts_where	Allows you to change the WHERE clause of an SQL query used to retrieve posts with WP_Query.
pre_get_posts	Allows changing a WP_Query query before it runs.
request	Filters the parameters (variables) of the main WordPress query.
wp	Fires immediately after the global WP object is set: the global `$wp` variable has been defined. The hook fires at the end of wp().