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| author | Noah Misch <noah@leadboat.com> | 2020-08-15 20:21:52 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2020-08-15 20:21:52 -0700 |
| commit | 676a9c3cc4b5f1d262c29de318868948513f0fa0 (patch) | |
| tree | 64edcf02ac31b655be3cd8d51dc8c298461fc7d7 /src/backend/access/transam/varsup.c | |
| parent | db659a3416b967d716806e558efbb9d1ec610cd1 (diff) | |
Correct several behavior descriptions in comments.
Reuse cautionary language from src/test/ssl/README in
src/test/kerberos/README. SLRUs have had access to six-character
segments names since commit 73c986adde5d73a5e2555da9b5c8facedb146dcd,
and recovery stopped calling HeapTupleHeaderAdvanceLatestRemovedXid() in
commit 558a9165e081d1936573e5a7d576f5febd7fb55a. The other corrections
are more self-evident.
Diffstat (limited to 'src/backend/access/transam/varsup.c')
| -rw-r--r-- | src/backend/access/transam/varsup.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c index 2d2b05be36c..a4944faa32e 100644 --- a/src/backend/access/transam/varsup.c +++ b/src/backend/access/transam/varsup.c @@ -367,12 +367,13 @@ SetTransactionIdLimit(TransactionId oldest_datfrozenxid, Oid oldest_datoid) * We'll refuse to continue assigning XIDs in interactive mode once we get * within 3M transactions of data loss. This leaves lots of room for the * DBA to fool around fixing things in a standalone backend, while not - * being significant compared to total XID space. (Note that since - * vacuuming requires one transaction per table cleaned, we had better be - * sure there's lots of XIDs left...) Also, at default BLCKSZ, this - * leaves two completely-idle segments. In the event of edge-case bugs - * involving page or segment arithmetic, idle segments render the bugs - * unreachable outside of single-user mode. + * being significant compared to total XID space. (VACUUM requires an XID + * if it truncates at wal_level!=minimal. "VACUUM (ANALYZE)", which a DBA + * might do by reflex, assigns an XID. Hence, we had better be sure + * there's lots of XIDs left...) Also, at default BLCKSZ, this leaves two + * completely-idle segments. In the event of edge-case bugs involving + * page or segment arithmetic, idle segments render the bugs unreachable + * outside of single-user mode. */ xidStopLimit = xidWrapLimit - 3000000; if (xidStopLimit < FirstNormalTransactionId) |