type = struct CheckPoint { 0 | 8 */ XLogRecPtr redo; 8 | 4 */ TimeLineID ThisTimeLineID; 12 | 4 */ TimeLineID PrevTimeLineID; 16 | 1 */ _Bool fullPageWrites; XXX 3-byte hole */ 20 | 4 */ uint32 nextXidEpoch; 24 | 4 */ TransactionId nextXid; 28 | 4 */ Oid nextOid; 32 | 4 */ MultiXactId nextMulti; 36 | 4 */ MultiXactOffset nextMultiOffset; 40 | 4 */ TransactionId oldestXid; 44 | 4 */ Oid oldestXidDB; 48 | 4 */ MultiXactId oldestMulti; 52 | 4 */ Oid oldestMultiDB; 56 | 8 */ pg_time_t time; 64 | 4 */ TransactionId oldestCommitTsXid; 68 | 4 */ TransactionId newestCommitTsXid; 72 | 4 */ TransactionId oldestActiveXid; XXX 4-byte padding */ total size (bytes): 80 */ .