diff options
| -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)))) |