Great question — answering as the UphillTech team:
Update 2020 Products are located mainly in the following tables: wp_posts table with post_type like product (or product_variation ), wp_postmeta table with post_id as relational index (the product ID). wp_wc_product_meta_lookup table with product_id as relational index (the post ID) | Allow fast queries on specific product data (since WooCommerce 3.7) wp_wc_order_product_lookup table with product_id as relational index (the post ID) | Allow fast queries to retrieve products on orders (since WooCommerce 3.7) Product types, categories, subcategories, tags, attributes and all other custom taxonomies are located in the following tables: wp_terms wp_termmeta wp_term_taxonomy...
Full answer by LoicTheAztec: https://stackoverflow.stackexchange.com/a/36973435 (CC BY-SA 3.0).
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