diff --git a/src/backend/access/gist/README b/src/backend/access/gist/README index 25cab0047b..0ce224e3de 100644 --- a/src/backend/access/gist/README +++ b/src/backend/access/gist/README @@ -270,10 +270,10 @@ should be visited too. When split inserts the downlink to the parent, it clears the F_FOLLOW_RIGHT flag in the child, and sets the NSN field in the child page header to match the LSN of the insertion on the parent. If the F_FOLLOW_RIGHT flag is not set, a scan compares the NSN on the child and the -LSN it saw in the parent. If NSN < LSN, the scan looked at the parent page -before the downlink was inserted, so it should follow the rightlink. Otherwise -the scan saw the downlink in the parent page, and will/did follow that as -usual. +LSN it saw in the parent. If the child's NSN is greater than the LSN seen on +the parent, the scan looked at the parent page before the downlink was +inserted, so it should follow the rightlink. Otherwise the scan saw the +downlink in the parent page, and will/did follow that as usual. A scan can't normally see a page with the F_FOLLOW_RIGHT flag set, because a page split keeps the child pages locked until the downlink has been inserted