On Fri, Dec 23, 2022 at 10:48 AM Hayato Kuroda (Fujitsu) <kuroda.hay...@fujitsu.com> wrote: > > ``` > + * If logical_decoding_mode is immediate, loop until there's no > change. > + * Otherwise, loop until we reach under the memory limit. One might > think > + * that just by evicting the largest (sub)transaction we will come > under > + * the memory limit based on assumption that the selected transaction > is > + * at least as large as the most recent change (which caused us to go > over > + * the memory limit). However, that is not true because a user can > reduce > + * the logical_decoding_work_mem to a smaller value before the most > recent > * change. > */ > ``` > > Do we need to pick the largest (sub)transaciton even if we are in the > immediate mode? > It seems that the liner search is done in > ReorderBufferLargestStreamableTopTXN() > to find the largest transaction, but in this case we can choose the arbitrary > one. >
In immediate mode, we will stream/spill each change, so ideally, we don't need to perform any search. Otherwise, also, I think changing those functions will complicate the code without serving any purpose. -- With Regards, Amit Kapila.
