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| author | Robert Haas <rhaas@postgresql.org> | 2019-05-13 13:13:24 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2019-05-13 13:13:24 -0400 |
| commit | 221b377f09a30dd7c74c26c8c1db439afcc59141 (patch) | |
| tree | 5767dddde1ce1c81a8fa044c5ed1702d4fecea1c /src | |
| parent | ddf927fb13471bec0cc76794eaf552df8a1178fb (diff) | |
| download | postgresql-221b377f09a30dd7c74c26c8c1db439afcc59141.tar.gz postgresql-221b377f09a30dd7c74c26c8c1db439afcc59141.zip | |
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
Diffstat (limited to 'src')
| -rw-r--r-- | src/include/access/tupmacs.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/include/access/tupmacs.h b/src/include/access/tupmacs.h index 7c62cf3bbc4..23cf481e785 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)))) |