SKIP LOCKED lets several workers claim different rows from one table without blocking each other, which is what makes a database usable as a queue. This is genuinely…
MySQL 8.0 changed the default collation, so a table created before an upgrade and one created after cannot be joined on a string column without a conversion. The…
A transient with an expiry is stored as two rows in the options table, and nothing deletes an expired one until something asks for it. Expired transients are…
Almost every MySQL tuning question is answered by whether the working set fits in the buffer pool, and almost every tuning guide starts somewhere else. A hit rate…
MySQL has no materialised views, so a summary table plus a refresh strategy is the manual equivalent, and the watermark is what makes the refresh incremental. The watermark…
An invisible index is maintained on write and ignored by the optimiser, which makes dropping an index a reversible experiment instead of a commitment. The write cost is…
Offset pagination over a list that changes between requests skips and duplicates rows, and it gets slower as the offset grows. The row-skipping is the correctness argument and…