no_found_rows argument for WP_Query does not exist but is used in Recent Posts widget

[alexvorn2]

in \wp-includes\widgets\class-wp-widget-recent-posts.php we have this argument in the array of arguments but in I can't find it in ​https://codex.wordpress.org/Class_Reference/WP_Query docs page.

I think it was used a long time ago and still have not been removed.

[helen]

If you look at the actual WP_Query class, it's in there, documented in the PHPDoc for WP_Query::parse_query(). If it needs to be added to the Codex page, it's a wiki. It's definitely an argument that works and is used frequently to scale queries better as appropriate.

[swissspidy]

See also ​https://developer.wordpress.org/reference/classes/wp_query/parse_query/ for an online version of the docs.

As already mentioned, feel free to update the Codex page.

[ocean90]

The Code Reference is the better resource if you want to know which function/class/method supports which arguments/properties.