Change the structure of important meta data fields to a horizontal/relational structure and give WordPress meta queries a performance kick.
A. No. Horizontal Meta should be tested with your installation and your WordPress configuration. For large sites, Horizontal Meta will most likely improve performance though not guaranteed. Horizontal Meta should only be used in conjunction with good coding practises. This includes the correct structuring of data types & the correct use of taxonomies. Meta Data should not be considered a quick fix, one solution fits all plugin. Advanced performance reviews are available for a fee by emailing firstname.lastname@example.org.
A. This may be because the meta key you are watching is being directly updated in the database rather than using the WordPress API. Your meta key may not be compatible with Horizontal Meta. If you are a developer, you may try to trace through the code to find out where the meta key is being updated. If the meta key is created an updated by a plugin, you may also send a request to the plugin developer and request they use the WordPress API to make updates and additions.
A. By default when the plugin is first installed, Horizontal Meta will not intercept your meta key queries unless you prefix each meta key with _horzm_. This is the recommended method of integrating Horizontal Meta into your website. You may also go to Advanced Settings and set the Intercept Meta Keys option to Yes. With this option set, Horizontal Meta will then reroute any keys that are being watched to Horizontal Meta. You should also double check to ensure you have mapped all the meta keys required for your queries. If you are trying to use Horizontal Meta with get_posts(), you must set the 'suppress_filters' arg to false, or else Horizontal Meta will not be called. If you have done this then perhaps Horizontal Meta is not going to increase the performance of your website and you should look to other solutions. NOTE: Horizontal Meta currently does not support the advanced querying features available in WordPress 4.1 and later! This may be available in the future.