Magento – Catalog URL Rewrites – Index product and categories URL rewrites – take long time to processing

Yes. This is a commonly encountered problem with magento URL rewriting system.

A short term solution can be to create the required system URL (using category or cms page) and then edit it.

System URLs are not deleted upon re-indexing.

I do not think there is an event that will cover all catalog rewrites (i.e. category, product and normal urls) but you could cover all three with the following events.

after_reindex_process_catalog_url_category
after_reindex_process_catalog_url_product
after_reindex_process_url_redirect

These are called after each index is completed and is fired via.

Mage::dispatchEvent('after_reindex_process_' . $this->getIndexerCode());

Where the indexer code is one of the following.

cataloginventory_stock
catalog_product_price
catalog_url_category
catalog_url_product
url_redirect
catalog_category_product
catalogsearch_fulltext
tag_summary
catalog_product_attribute