wp-transients-api-term.php

<?php
/**
 * The Transients API is very similar to the Options API but with the added feature of an expiration time,
 * which simplifies the process of using the wp_options database table to temporarily store cached information.
 * Reference: https://codex.wordpress.org/Transients_API
 */

// Get any existing copy of our transient data
if ( false === ( $special_query_results = get_transient( 'special_query_results' ) ) ) {
    // It wasn't there, so regenerate the data and save the transient
     $special_query_results = new WP_Query( 'cat=5&order=random&tag=tech&post_meta_key=thumbnail' );
     set_transient( 'special_query_results', $special_query_results, 12 * HOUR_IN_SECONDS );
}

// Use the data like you would have normally...

// Create a simple function to delete our transient
function edit_term_delete_transient() {
     delete_transient( 'special_query_results' );
}
// Add the function to the edit_term hook so it runs when categories/tags are edited
add_action( 'edit_term', 'edit_term_delete_transient' );