Hi All, prologue of pg_dump.c says * Note that pg_dump runs in a transaction-snapshot mode transaction, * so it sees a consistent snapshot of the database including system * catalogs. However, it relies in part on various specialized backend * functions like pg_get_indexdef(), and those things tend to look at * the currently committed state. So it is possible to get 'cache * lookup failed' error if someone performs DDL changes while a dump is * happening. The window for this sort of thing is from the acquisition * of the transaction snapshot to getSchemaData() (when pg_dump acquires * AccessShareLock on every table it intends to dump). It isn't very large, * but it can happen.
But this possible failure has not been documented at https://www.postgresql.org/docs/12/app-pgdump.html. Although the window for failure is small, it's not impossible.Should we document this kind of failure? -- Best Wishes, Ashutosh Bapat
