[重慶思莊每日技術分享]-expdp導資料時評估匯出檔案大小

使用expdp匯出命令時，通常需要評估匯出檔案的大小來作為空間是否足夠的依據，

特別是在做全庫匯出的場景中。

設定引數estimate_only=y|n 來指定是否僅做評估而不導資料

設定引數estimate=statistic 根據最近統計值估算物件佔用空間

測試過程如下：

[oracle@hisdb1:/home/oracle]$ expdp \'/ as sysdba\' full=y estimate_only=y estimate=statistics

Export: Release 11.2.0.4.0 - Production on Fri Feb 18 16:20:27 2022

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,

Data Mining and Real Application Testing options

Starting "SYS"."SYS_EXPORT_FULL_01":  "/******** AS SYSDBA" full=y estimate_only=y estimate=statistics

Estimate in progress using STATISTICS method...

.  estimated "SYSTEM"."REPCAT$_RESOLUTION_STATISTICS"        0 KB

.  estimated "SYSTEM"."REPCAT$_RESOL_STATS_CONTROL"          0 KB

.  estimated "SYSTEM"."REPCAT$_RUNTIME_PARMS"                0 KB

.  estimated "SYSTEM"."REPCAT$_SITES_NEW"                    0 KB

.  estimated "SYSTEM"."REPCAT$_SITE_OBJECTS"                 0 KB

.  estimated "SYSTEM"."REPCAT$_SNAPGROUP"                    0 KB

.  estimated "SYSTEM"."REPCAT$_TEMPLATE_OBJECTS"             0 KB

.  estimated "SYSTEM"."REPCAT$_TEMPLATE_PARMS"               0 KB

.  estimated "SYSTEM"."REPCAT$_TEMPLATE_REFGROUPS"           0 KB

.  estimated "SYSTEM"."REPCAT$_TEMPLATE_SITES"               0 KB

.  estimated "SYSTEM"."REPCAT$_TEMPLATE_TARGETS"             0 KB

.  estimated "SYSTEM"."REPCAT$_USER_AUTHORIZATIONS"          0 KB

.  estimated "SYSTEM"."REPCAT$_USER_PARM_VALUES"             0 KB

.  estimated "SYSTEM"."SQLPLUS_PRODUCT_PROFILE"              0 KB

Total estimation using STATISTICS method: 29.25 MB

Job "SYS"."SYS_EXPORT_FULL_01" successfully completed at Fri Feb 18 16:20:42 2022 elapsed 0 00:00:14