數據庫導出中的問題

我計劃在每個午夜通過 Windows 任務計劃程序導出我的數據庫。這被正確地導出了這麼長時間。但是，最近在某些日子裡，出口並未按要求進行。日誌顯示以下錯誤。

Processing object type DATABASE_EXPORT/SCHEMA/POST_SCHEMA/PROCOBJ
Processing object type DATABASE_EXPORT/SCHEMA/POST_SCHEMA/PROCACT_SCHEMA
Processing object type DATABASE_EXPORT/AUDIT
. . exported "AAAA"."AA_DETAILS"                 881.0 MB   36568 rows
ORA-31693: Table data object "AA"."PS_TXN" failed to load/unload and is being skipped due to error:
ORA-02354: error in exporting/importing data
ORA-01555: snapshot too old: rollback segment number  with name "" too small
ORA-22924: snapshot too old
. . exported "APEX_030200"."WWV_FLOW_STEP_PROCESSING"    1.248 MB    2238 rows
. . exported "APEX_030200"."WWV_FLOW_REGION_REPORT_COLUMN"  1.146 MB    7903 rows
..
. . exported "SYSMAN"."MGMT_BLACKOUT_SCHEDULE"           11.51 KB       0 rows
. . exported "SYSMAN"."MGMT_COLLECTIONS"                 32.67 KB     202 rows
ORA-31693: Table data object "SYSMAN"."MGMT_COLLECTION_TASKS" failed to load/unload and is being skipped due to error:
ORA-02354: error in exporting/importing data
ORA-01555: snapshot too old: rollback segment number 6 with name "_SYSSMU6_2560781624$" too small
. . exported "SYSMAN"."MGMT_DB_INIT_PARAMS_ECM"          25.67 KB     352 rows
. . exported "SYSMAN"."MGMT_ECM_MD_ALL_TBL_COLUMNS"      110.2 KB     704 rows
. . exported "SYSMAN"."MGMT_INV_COMPONENT"               46.15 KB     144 rows
. . exported "SYSMAN"."MGMT_IP_SQL_STATEMENTS"           64.57 KB      31 rows
. . exported "SYSMAN"."MGMT_JOB_PARAM_SOURCE"            79.73 KB     527 rows
. . exported "SYSMAN"."MGMT_JOB_SCHEDULE"                11.13 KB       2 rows
. . exported "SYSMAN"."MGMT_JOB_SEC_INFO"                    9 KB       7 rows
. . exported "SYSMAN"."MGMT_JOB_USER_PARAMS"             7.515 KB      15 rows
. . exported "SYSMAN"."MGMT_LOADER_QTABLE"               16.68 KB       0 rows
. . exported "SYSMAN"."MGMT_NOTIFY_INPUT_QTABLE"         16.69 KB       0 rows
ORA-31693: Table data object "SYSMAN"."MGMT_SYSTEM_PERFORMANCE_LOG" failed to load/unload and is being skipped due to error:
ORA-02354: error in exporting/importing data
ORA-01555: snapshot too old: rollback segment number 15 with name "_SYSSMU15_3269182342$" too small
. exported "XX"."AAA"                   15.97 KB      11 rows
ORA-31693: Table data object "XX"."AAA" failed to load/unload and is being skipped due to error:
ORA-02354: error in exporting/importing data
ORA-01555: snapshot too old: rollback segment number 15 with name "_SYSSMU15_3269182342$" too small
. . exported "SYSMAN"."ESM_COLLECTION"                   23.32 KB     219 rows
. . exported "SYSMAN"."MGMT_AGENT_SEC_INFO"              7.960 KB       1 rows
. . exported "SYSMAN"."MGMT_ARU_PRODUCT_RELEASE_MAP"     84.79 KB    5956 rows
. . exported "SYSMAN"."MGMT_CATEGORY_MAP"                46.76 KB     637 rows
. . exported "SYSMAN"."MGMT_CURRENT_VIOLATION"           61.67 KB     161 rows
. . exported "SYSMAN"."MGMT_DB_RECSEGMENTSETTINGS_ECM"   23.33 KB     200 rows
. . exported "SYSMAN"."MGMT_ECM_SNAPSHOT_MD_COLUMNS"     87.19 KB     839 rows
. . exported "SYSMAN"."MGMT_IP_ELEM_DEFAULT_PARAMS"      31.75 KB     130 rows
. . exported "SYSMAN"."MGMT_JOB_COMMAND_BLOCK_PROCS"     5.914 KB       3 rows
. . exported "SYSMAN"."MGMT_JOB_LARGE_PARAMS"            5.929 KB       2 rows
. . exported "SYSMAN"."MGMT_JOB_OUTPUT"                  5.859 KB       0 rows
. . exported "SYSMAN"."MGMT_JOB_PARAMETER"               8.859 KB       2 rows
. . exported "SYSMAN"."MGMT_JOB_SQL_PARAMS"              6.828 KB       7 rows
. . exported "SYSMAN"."MGMT_JOB_SUBST_PARAMS"            6.296 KB      13 rows
. . exported "SYSMAN"."PARAM_VALUES_TAB"                 21.74 KB     240 rows
. . exported "SYSMAN"."MGMT_LAST_VIOLATION"              56.28 KB     762 rows
. . exported "SYSMAN"."MGMT_LICENSE_DEFINITIONS"         54.65 KB      59 rows
. . exported "SYSMAN"."MGMT_NOTIFY_QTABLE"               22.36 KB       0 rows
. . exported "SYSMAN"."MGMT_PAF_MSG_QTABLE_1"            18.85 KB       0 rows
. . exported "SYSMAN"."MGMT_PAF_MSG_QTABLE_2"            18.85 KB       0 rows
. . exported "SYSMAN"."MGMT_POLICY_ASSOC_CFG_PARAMS"     61.80 KB     715 rows
ORA-31693: Table data object "SYSMAN"."MGMT_POLICY_ASSOC_EVAL_DETAILS" failed to load/unload and is being skipped due to error:
ORA-02354: error in exporting/importing data
ORA-01555: snapshot too old: rollback segment number 6 with name "_SYSSMU6_2560781624$" too small
. . exported "SYSMAN"."MGMT_POLICY_TYPE_VERSIONS"        20.38 KB     585 rows
. . exported "SYSMAN"."MGMT_POLICY_VIOL_CTXT_DEF"        68.09 KB     642 rows
ORA-31693: Table data object "SYSMAN"."MGMT_TASK_QTABLE" failed to load/unload and is being skipped due to error:
ORA-29913: error in executing ODCIEXTTABLEPOPULATE callout
ORA-01555: snapshot too old: rollback segment number 19 with name "_SYSSMU19_255734752$" too small

雖然我對這方面了解不多，但我只是通過使用以下命令增加 UNDO 表空間的保留策略來增加嘗試。

更改系統設置 undo_retention = 16500 範圍 = 兩者；

但我仍然遇到同樣的錯誤。這發生在間歇性的日子裡。另外，我的數據庫有點大，所以我刪除了一些不需要的數據並釋放了一些空間。現在，大小低於 10GB。這也沒有幫助。我被困住了。任何人都可以幫助解決數據庫導出中的此錯誤。

即使撤消保留時間長且撤消表空間很大，如果您在作業執行時經常送出，仍然可能會遇到這種情況。這是因為您會將您的工作分散在許多撤消段中，越來越有可能出現一個過時的情況。

你的工作需要超過四小時三十五分鐘嗎？您的 undo_retention 可能仍然太低。

如果不這樣做，請嘗試在導出中使用 FLASHBACK_SCN 參數。例如：

select CURRENT_SCN from v$database;

FLASHBACK_SCN=9883682053912
FULL=Y
DIRECTORY=DUMP
DUMPFILE=DZMW_FULL.dmp
LOGFILE=export_FULL.log
JOB_NAME=EXPFULL
PARALLEL=16

引用自：https://dba.stackexchange.com/questions/162612