Partitioning and replica

[GiovanniGoccia]

hello, i am configuring wordpress to move the postmeta table to a second db in write and read using your Partitioning guide. The procedure works but I was wondering if it was possible to have a write also in the primary db so that the postmeta tables between the 2 db are always the same.
With partitioning this does not happen and the postmeta table is only updated in the second db via the callback

global $wpdb;
$wpdb->add_callback( 'db_callback' );
function db_callback( $query, $wpdb ) {
if ($wpdb->base_prefix . 'postmeta' == $wpdb->table ) {
return 'wpposts';
}
}

what can I do to have the 2 tables always identical but only read from the second db?

[JJJ]

This should be possible as long as you have your object & meta pairs on the same server (posts & postmeta). If you need them to be on different servers, you'll need to do a bunch more work than most people care to do.

Can you share here the code you're using to add your databases?