Week 04 Lectures (22)

PostgreSQL Tuples (cont)

Some of the bits in t_infomask ..

#define HEAP_HASNULL      0x0001
        /* has null attribute(s) */
#define HEAP_HASVARWIDTH  0x0002
        /* has variable-width attribute(s) */
#define HEAP_HASEXTERNAL  0x0004
        /* has external stored attribute(s) */
#define HEAP_HASOID_OLD   0x0008 
        /* has an object-id field */

Location of NULLs is stored in t_bits[] array