PostgreSQL
4 focused explainers for readers who want the useful answer, a clear example, and a practical next step.
PostgreSQL COPY REJECT_LIMIT: safer bulk imports without hiding bad data
REJECT_LIMIT can keep a bulk load moving through a small number of malformed rows, but rejected data still needs an auditable.
PostgreSQL 18 EXPLAIN memory and disk fields: read them correctly
New EXPLAIN details make spills easier to see, but one execution is not enough to choose work_mem or rewrite a.
PostgreSQL 18 skip scans: when a multicolumn index starts helping
Skip scans let PostgreSQL use some multicolumn B-tree indexes even when the leading column is not constrained, but they do not make every index order.
PostgreSQL 18 asynchronous I/O: what backend teams should measure
Asynchronous I/O can improve scans and vacuum work, but an upgrade benchmark must separate storage latency, cache effects, and query-plan.