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PARALLEL INDEX CREATION SIGNIFICANTLY INCREASING DATAFILE SIZE IN 12C AND LATER VERSIONS (Doc ID 2760369.1)

Last updated on MARCH 18, 2021

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Information in this document applies to any platform.

Symptoms

Parallel index creation on Bigfile Tablespace is significantly increasing datafile size in 12c and later versions

In 11.2.0.4,
1.Create a "Bigfile Tablespace"
2.Create a test table
3.Create a index on the test table using PARALLEL clause/option on bigfile TS
4.File size from dba_data_files is showing as 384MB.
select FILE_NAME,sum(bytes)/1024/1024 from dba_data_files where FILE_NAME
like('%<dbfile_name_created_for_bigfile_ts>%') group by FILE_NAME;

Now, by following same steps as above in later versions like 12,18c and 19c,
TS/Datafile size is getting increased to 896MB. Which is high when compared with 11g TS/Datafile size(384MB).

Below is a simple test case from 12c later version

 

Changes

 DB upgraded from 11g

Cause

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In this Document
Symptoms
Changes
Cause
Solution
References


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