From ff0bdc666946bc0ec303bfc2df1e0efa4751f119 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 15 Oct 2021 10:16:10 -0400 Subject: [PATCH] update README --- src/backend/access/conveyor/README | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/src/backend/access/conveyor/README b/src/backend/access/conveyor/README index 54c0230263..0314abc664 100644 --- a/src/backend/access/conveyor/README +++ b/src/backend/access/conveyor/README @@ -98,9 +98,13 @@ Removing Old Data ----------------- From time to time, we expect to receive a request to discard old data, -which will come in the form of a statement that all logical pages with -page numbers less than some threshold value are no longer required. We -proceed as follows: +which will come in the form of a call to ConveyorBeltLogicalTruncate stating +that all logical pages with page numbers less than some threshold value are +no longer required. Thereafter, a subsequent call to ConveyorBeltVacuum +may be used to free up any segments that are no longer required as a result +of the increased logical truncation point. The overall process looks like +this, with the first step being performed by ConveyorBeltLogicalTruncate +and the remaining steps by ConveyorBeltVacuum: 1. Update the metapage with the new threshold value. Once this has been done, attempts to access logical pages prior to the new threshold will -- 2.39.5