After Compressing A Table With More Than 255 Columns Then Its Size Is Lager (Doc ID 989484.1)

Last updated on MAY 12, 2017

Applies to:

Oracle Server - Enterprise Edition - Version: 10.2.0.1 to 11.2.0.2.0 - Release: 10.2 to 11.2
Information in this document applies to any platform.

Symptoms


Once that a table with more than 255 columns has been compressed, then its size is more than when it was
an uncompressed table. This happens even when there are duplicate values.

Reviewed the information by commands:

SQL> select sum(bytes)/(1024*1024) from dba_segments where SEGMENT_NAME='TABLE_NAME';
SQL> select EXTENT_ID,BLOCKS from dba_extents where SEGMENT_NAME like 'TABLE_NAME';
SQL> select pct_free,pct_used from dba_tables where table_name='TABLE_NAME';

Cause

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