Data Pump - Estimating the Size of Export Jobs

If you’re about to export a large amount of data, you can estimate the size of the file that Data Pump creates before you run the export. You may want to do this because you’re concerned about the amount of space an export job needs.

To estimate the size, use the ESTIMATE_ONLY parameter. This example estimates the size of the export file for an entire database:

$ expdp dbauser/foo estimate_only=y full=y logfile=n

Here’s a snippet of the output:

Estimate in progress using BLOCKS method...
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/TABLE_DATA
. estimated "REP_MV"."REG_QUEUE_REP" 9.606 GB
. estimated "REP_MV"."CWP_USER_PROFILE" 2.589 GB
. estimated "REP_MV"."PRODUCT_INSTANCES_MV" 1.620 GB
. estimated "REP_MV"."ROLES_MV" 1.550 GB
. estimated "STAR2"."F_DOWNLOADS":"DOWN_P_5" 1.450 GB
. estimated "STAR2"."F_DOWNLOADS":"DOWN_P_11" 1.414 GB

Similarly, you can specify a schema name to get an estimate of the size required to export a user:

$ expdp dbauser/foo estimate_only=y schemas=star2 logfile=n

Here’s an example of estimating the size required for two tables:

$ expdp dbauser/foo estimate_only=y tables=star2.f_downloads,star2.f_installations logfile=n