When two rows compare equal under the window’s ORDER BY, the numbering between them is arbitrary and MySQL is free to choose differently on the next execution. The…
Two deployables writing the same tables is one service with extra steps. Deciding who owns them is the whole decision, and the intermediate state lasts.
Earlier versions parsed DESC in an index definition and ignored it, which is worse than rejecting it — the index looked right and the query did a filesort.…
Options, tables, scheduled events, user meta and post meta all survive deactivation and deletion unless the plugin removes them explicitly, and most do not. The constant check is…
3.6 in April added wc_product_meta_lookup, a flat table of the attributes catalogue queries filter on — which is WooCommerce accepting that postmeta does not scale. The table is…
An index on (a) is redundant when an index on (a, b) exists, because the composite serves every query the single-column one could — and both are being…