WordPress at a glance
filter is not described

found_sites_query filter-hook . WP 4.6.0

Filters the query used to retrieve found site count.

Usage

add_filter( 'found_sites_query', 'filter_function_name_1316', 10, 2 );
function filter_function_name_1316( $found_sites_query, $site_query ){
	// filter...

	return $found_sites_query;
}
$found_sites_query(string)
SQL query.
Default: 'SELECT FOUND_ROWS()'
$site_query(WP_Site_Query)
The WP_Site_Query instance.

Where the hook is called

WP_Site_Query::set_found_sites()
wp-includes/class-wp-site-query.php 604
$found_sites_query = apply_filters( 'found_sites_query', 'SELECT FOUND_ROWS()', $this );

Where the hook is used (in WP core)

Does not used.