Remove remants of "snapshot too old"
Remove the 'whenTaken' and 'lsn' fields from SnapshotData. After the
removal of the "snapshot too old" feature, they were never set to a
non-zero value.
This largely reverts commit 3e2f3c2e423, which added the
OldestActiveSnapshot tracking, and the init_toast_snapshot()
function. That was only required for setting the 'whenTaken' and 'lsn'
fields. SnapshotToast is now a constant again, like SnapshotSelf and
SnapshotAny. I kept a thin get_toast_snapshot() wrapper around
SnapshotToast though, to check that you have a registered or active
snapshot. That's still a useful sanity check.
Reviewed-by: Nathan Bossart, Andres Freund, Tom Lane
Discussion: https://www.postgresql.org/message-id/cd4b4f8c-e63a-41c0-95f6-6e6cd9b83f6d@iki.fi
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/4d8275046c36792afb3604677c0a53c8530388ae
Modified Files
--------------
contrib/amcheck/verify_heapam.c | 4 +--
src/backend/access/common/toast_internals.c | 51 ++++++++++-----------------
src/backend/access/heap/heaptoast.c | 4 +--
src/backend/storage/ipc/procarray.c | 4 ---
src/backend/utils/time/snapmgr.c | 54 +----------------------------
src/include/access/genam.h | 2 ++
src/include/access/toast_internals.h | 2 +-
src/include/storage/predicate.h | 1 +
src/include/utils/snapmgr.h | 13 ++-----
src/include/utils/snapshot.h | 7 ----
10 files changed, 28 insertions(+), 114 deletions(-)
