Reword comment for clarity

Reported by Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoB+ycZ2z-4Ye=6MfQ_r0aV5r6cvVPw4kOyPdp6bHqQoBQ@mail.gmail.com

diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 153d1712ef3a2cef4452f8f00a03a722ba6e4057..0ca4fa5d25665b8024d496654d6e762cb4a80532 100644 (file)
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -1116,9 +1116,9 @@ SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xact
         * so, because we only need to do it for catalog transactions since we
         * only ever look at those.
         *
-        * NB: Because of that xmax can be lower than xmin, because we only
-        * increase xmax when a catalog modifying transaction commits. While odd
-        * looking, it's correct and actually more efficient this way since we hit
+        * NB: We only increase xmax when a catalog modifying transaction commits
+        * (see SnapBuildCommitTxn).  Because of this, xmax can be lower than xmin,
+        * which looks odd but is correct and actually more efficient, since we hit
         * fast paths in tqual.c.
         */
        builder->xmin = running->oldestRunningXid;