Also called: SLRU statistics view
In plain English
pg_stat_slru is a system view (PostgreSQL 13+) that reports activity for each internal SLRU cache — one row per cache (CommitTs, MultiXactMember, MultiXactOffset, Subtrans, Xact, and others). Its columns count buffer hits, disk reads, writes, and pages zeroed.
Why it matters
It is the instrument for diagnosing SLRU contention. Rising blks_read on the Subtrans row points to subtransaction overflow; growth on the MultiXact* rows points to heavy row-share locking. Without this view, SLRU pressure is nearly invisible — with it, you can target exactly which cache to enlarge (PG17 buffer GUCs) or which workload to fix.