WordPress - Check for autoload options, if it's more than 1 MB then it will show admin notice in Admin area - Not for VIP environment.

vk-rt-limit-options.php

<?php

/**
 * Plugin Name: All Options Limit for WordPress
 * Description: Provides warnings and notifications for wp_options exceeding limits.
 * Author: Vishal
 * License: GPL version 2 or later - http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

/**
 * Inspired by VIP Go MU plugins.
 * Ref: https://raw.githubusercontent.com/Automattic/vip-go-mu-plugins/master/alloptions-limit.php
 */

function vk_get_auto_load_options_size() {

	$options_size = wp_cache_get( 'rt_all_autoload_options_size', 'rt_all_options_cache' );

	// Cache miss
	if ( false === $options_size ) {

		$options = wp_load_alloptions();

		// Strlen returns bytes.
		$options_size = strlen( maybe_serialize( $options ) );

		wp_cache_set( 'rt_all_autoload_options_size', $options_size, 'rt_all_options_cache', 30 * MINUTE_IN_SECONDS );
	}

	return $options_size;
}

function vk_convert_to_readable_size( $size ) {

	$base = log( $size ) / log( 1000 );

	$suffix = array( '', ' KB', ' MB', ' GB', ' TB' );

	$f_base = floor( $base );

	return round( pow( 1000, $base - floor( $base ) ), 1 ) . $suffix[ $f_base ];
}

function rt_give_admin_notice() {

	if ( defined( 'WP_CLI' ) && WP_CLI ) {
		return;
	}

	$options_size = vk_get_auto_load_options_size();

	// If it's over the warning threshold notify.
	if ( $options_size > 1000000 ) { // 1000000 bytes ~ 1MB, too big for cache.

		$readable_size = vk_convert_to_readable_size( $options_size );

		// NOTE - This function has built-in rate limiting so it's ok to call on every request.
		?>

		<div class="notice notice-error is-dismissible">
			<h3><?php esc_html_e( 'Too big options table!', 'rt-limit-options' ); ?></h3>
			<p>
				<?php
				// translators: Autoload options size.
				printf( esc_html__( 'Your database\'s autoload options size(%s) is exceeds than 1 MB.', 'rt-limit-options' ), esc_html( $readable_size ) );
				?>
			</p>
		</div>

		<?php
	}
}
add_action( 'admin_notices', 'rt_give_admin_notice', 1 );