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Why is the Export Dump File Size Bigger than the Segment Size? (Doc ID 752172.1)

Last updated on JANUARY 30, 2022

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 9.2 to 11.1]
Oracle Database - Enterprise Edition - Version and later
Oracle Database Cloud Schema Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.


You started a table export using the original export utility (exp) or DataPump utility (expdp) and observed that the size of the written export dump is bigger than the segment size in data dictionary.

Let's follow the next example to visualize this.

1. Normal table for reference

=> In case the table has many NULL columns at the end, the DataPump export dump file size is 10,899,456 bytes and the segment size is 13,631,488 bytes.


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