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authorRobert Haas2019-05-13 17:13:24 +0000
committerRobert Haas2019-05-13 17:13:24 +0000
commit221b377f09a30dd7c74c26c8c1db439afcc59141 (patch)
tree5767dddde1ce1c81a8fa044c5ed1702d4fecea1c
parentddf927fb13471bec0cc76794eaf552df8a1178fb (diff)
Improve comment for att_isnull.
The comment implies that a 1 in the null bitmap indicates a null value, but actually a 0 in the null bitmap indicates a null value. Try to be more clear. Patch by me; proposed wording reviewed by Alvaro Herrera and Tom Lane. Discussion: http://postgr.es/m/CA+TgmobHOP8r6cG+UnsDFMrS30-m=jRrCBhgw-nFkn0k9QnFsg@mail.gmail.com
-rw-r--r--src/include/access/tupmacs.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/src/include/access/tupmacs.h b/src/include/access/tupmacs.h
index 7c62cf3bbc..23cf481e78 100644
--- a/src/include/access/tupmacs.h
+++ b/src/include/access/tupmacs.h
@@ -16,7 +16,9 @@
/*
- * check to see if the ATT'th bit of an array of 8-bit bytes is set.
+ * Check a tuple's null bitmap to determine whether the attribute is null.
+ * Note that a 0 in the null bitmap indicates a null, while 1 indicates
+ * non-null.
*/
#define att_isnull(ATT, BITS) (!((BITS)[(ATT) >> 3] & (1 << ((ATT) & 0x07))))