积累增量和差异增量：
对于 RMAN 来说，积累增量备份和差异增量备份都是增量备份的一种形式，它们之间的区别在于备份的范围和备份集的方式。
- 积累增量备份：在进行积累增量备份时，RMAN 会备份自最后一次完全备份或增量备份以来所做的所有更改数据，并将这些更改应用到备份集中。这样可以保证备份集中包含完整的数据集变化历史，并且能够恢复到任意时间点。
积累增量备份命令示例：
BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE;
- 差异增量备份：在进行差异增量备份时，RMAN 会备份自最后一次完全备份以来所做的所有更改数据，但不会将这些更改应用到备份集中。相反，RMAN 会创建一个只包含最新增量备份数据的备份集。因此，差异增量备份的备份集更小，还原数据需要使用完全备份和最近的差异增量备份。
差异增量备份命令示例：
BACKUP INCREENTAL LEVEL 1 DATABASE;
备份策略：
shell脚本编写oracle rman增量备份，如果是星期天执行0级增量，如果是星期三执行积累增量，星期六执行全量备份其余均执行差异增量备份
#!/bin/bash
export DBNAME=orclcdb
export ORACLE_SID=orclcdb
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/19.0.0/dbhome_1
export PATH=$ORACLE_HOME/bin:$HOME/bin:$PATH
export BACPATH=/u01/app/oracle/oradata/backup
export BACTIME=`date "+%Y-%m-%d"`
export LGNAME=rman_backup_`date "+%Y-%m-%d"`.log
mkdir ${BACPATH}/$BACTIMEcurrent_day=$(date +%A) # 获取当前星期几if [ "$current_day" = "Sunday" ]; then# 执行0级增量备份rman target / > ${BACPATH}/${BACTIME}/${LGNAME} << EOF run{CONFIGURE RETENTION POLICY TO REDUNDANCY 7;CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '${BACPATH}/${BACTIME}/${DBNAME}_ful_%U'; ALLOCATE CHANNEL c1 DEVICE TYPE DISK; BACKUP INCREMENTAL LEVEL 0 DATABASE format '${BACPATH}/${BACTIME}/${DBNAME}_ful0_data_file_%d_%T_%s_%p_%u';sql 'alter system archive log current';backup archivelog all format '${BACPATH}/${BACTIME}/${DBNAME}_arc_%U';backup current controlfile format '${BACPATH}/${BACTIME}/${DBNAME}_ctl_%U';backup spfile format '${BACPATH}/${BACTIME}/${DBNAME}_spf_%U';release channel c1;}quitEOFelif [ "$current_day" = "Wednesday" ]; then# 执行积累增量备份rman target / > ${BACPATH}/${BACTIME}/${LGNAME} << EOF run{CONFIGURE RETENTION POLICY TO REDUNDANCY 7;CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '${BACPATH}/${BACTIME}/${DBNAME}_ful_%U_%I'; ALLOCATE CHANNEL c1 DEVICE TYPE DISK; BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE format '${BACPATH}/${BACTIME}/${DBNAME}_fulCUM_data_file_%d_%T_%s_%p_%u_%I';sql 'alter system archive log current';backup archivelog all format '${BACPATH}/${BACTIME}/${DBNAME}_arc_%U_%I';backup current controlfile format '${BACPATH}/${BACTIME}/${DBNAME}_ctl_%U_%I';backup spfile format '${BACPATH}/${BACTIME}/${DBNAME}_spf_%U_%I';release channel c1;}quitEOFelif [ "$current_day" = "Saturday" ]; then# 执行全量备份rman target / > ${BACPATH}/${BACTIME}/${LGNAME} << EOF run{CONFIGURE RETENTION POLICY TO REDUNDANCY 7;CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '${BACPATH}/${BACTIME}/${DBNAME}_ful_%U_%I'; ALLOCATE CHANNEL c1 DEVICE TYPE DISK; BACKUP DATABASE format '${BACPATH}/${BACTIME}/${DBNAME}_ful_data_file_%d_%T_%s_%p_%u_%I';sql 'alter system archive log current';backup archivelog all format '${BACPATH}/${BACTIME}/${DBNAME}_arc_%U_%I';backup current controlfile format '${BACPATH}/${BACTIME}/${DBNAME}_ctl_%U_%I';backup spfile format '${BACPATH}/${BACTIME}/${DBNAME}_spf_%U_%I';release channel c1;}quitEOFelse# 执行差异增量备份rman target / > ${BACPATH}/${BACTIME}/${LGNAME} << EOF run{CONFIGURE RETENTION POLICY TO REDUNDANCY 7;CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '${BACPATH}/${BACTIME}/${DBNAME}_ful_%U_%I'; ALLOCATE CHANNEL c1 DEVICE TYPE DISK; BACKUP INCREMENTAL LEVEL 1 DATABASE format '${BACPATH}/${BACTIME}/${DBNAME}_fulINC_data_file_%d_%T_%s_%p_%u_%I';sql 'alter system archive log current';backup archivelog all format '${BACPATH}/${BACTIME}/${DBNAME}_arc_%U_%I';backup current controlfile format '${BACPATH}/${BACTIME}/${DBNAME}_ctl_%U_%I';backup spfile format '${BACPATH}/${BACTIME}/${DBNAME}_spf_%U_%I';release channel c1;}quitEOFfi
