Difference between index catalog_category_product and catalog_product_category

Question

Could someone explain me what is the difference between the indexes catalog_category_product and catalog_product_category?

From db i see that catalog_category_product is related to table catalog_category_product_index, but i don't find to which table is related catalog_product_category index.

Answer 1

The real difference is in the partial reindexing features:

• the catalog_category_product index reindexes partially by Category ID (accepts list of category IDs to reindex);
• the catalog_product_category index reindexes partially by Product ID (accepts list of product IDs to reindex);

Both act on the same database tables, it's just the input that differs.

Answer 2

Looking deep in magento core files, you notice that catalog_product_category index model is Magento\Catalog\Model\Indexer\Product\Category that extends Magento\Catalog\Model\Indexer\Category\Product that is the model of catalog_category_product index.

Both of them $fullActionFactory and $rowsActionFactory entities extends from Magento\Catalog\Model\Indexer\Category\Product\AbstractAction that has

const MAIN_INDEX_TABLE = 'catalog_category_product_index';

So we can say that both indexer works and save data on the same table catalog_category_product_index.

Answer 3

catalog_product_category : the "true" data saved by product. Those are the categories checked in the back-office when you edit the product.

catalog_product_category_index : where the product are "really". Meaning, if the parent category has "is_anchor" at yes, it means it has also the children category in it. So, it's "normal" to have both of those table.