diff options
| author | Tom Lane | 2013-12-12 17:40:00 +0000 |
|---|---|---|
| committer | Tom Lane | 2013-12-12 17:40:00 +0000 |
| commit | 17776250a5d3daca1c07dac59436932206b72aed (patch) | |
| tree | 0462e5b044acc9ff7c382a63987f2ef3e4823def | |
| parent | 52c342dd0241f18c16975da309585cfbc69e36d3 (diff) | |
Fix ancient docs/comments thinko: XID comparison is mod 2^32, not 2^31.
Pointed out by Gianni Ciolli.
| -rw-r--r-- | doc/src/sgml/maintenance.sgml | 2 | ||||
| -rw-r--r-- | src/backend/access/transam/transam.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index 1a5258b9490..ba8323c0946 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -359,7 +359,7 @@ as <literal>FrozenXID</>. This XID does not follow the normal XID comparison rules and is always considered older than every normal XID. Normal XIDs are - compared using modulo-2<superscript>31</> arithmetic. This means + compared using modulo-2<superscript>32</> arithmetic. This means that for every normal XID, there are two billion XIDs that are <quote>older</> and two billion that are <quote>newer</>; another way to say it is that the normal XID space is circular with no diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c index bc02f15e868..cc99cb93b31 100644 --- a/src/backend/access/transam/transam.c +++ b/src/backend/access/transam/transam.c @@ -305,7 +305,7 @@ TransactionIdPrecedes(TransactionId id1, TransactionId id2) { /* * If either ID is a permanent XID then we can just do unsigned - * comparison. If both are normal, do a modulo-2^31 comparison. + * comparison. If both are normal, do a modulo-2^32 comparison. */ int32 diff; |