type = struct CheckPoint { 0 | 8 */ XLogRecPtr redo; 8 | 4 */ TimeLineID ThisTimeLineID; 12 | 4 */ TimeLineID PrevTimeLineID; 16 | 1 */ _Bool fullPageWrites; XXX 7-byte hole */ 24 | 8 */ FullTransactionId nextXid; 32 | 4 */ Oid nextOid; 36 | 4 */ MultiXactId nextMulti; 40 | 4 */ MultiXactOffset nextMultiOffset; 44 | 4 */ TransactionId oldestXid; 48 | 4 */ Oid oldestXidDB; 52 | 4 */ MultiXactId oldestMulti; 56 | 4 */ Oid oldestMultiDB; XXX 4-byte hole */ 64 | 8 */ pg_time_t time; 72 | 4 */ TransactionId oldestCommitTsXid; 76 | 4 */ TransactionId newestCommitTsXid; 80 | 4 */ TransactionId oldestActiveXid; XXX 4-byte padding */ total size (bytes): 88 */.