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ALTER TABLE table_name MODIFY LOB (lob_name) (SHRINK SPACE);

ExorSep 15 2015 — edited Sep 16 2015

Hello,

I was doing a test to estimate possible savings of rebuilding a table; for my test I created a table, got the size of the lob segments with

select sum(dbms_lob.getlength (lob_column_name)) from table_name

for all 4 lob columns;

I then deleted 30% of the records in the table; reorged the table with dbms_redefinition; shrunk the lob segments (or so I thought with ALTER TABLE table_name MODIFY LOB (lob_column_name) (SHRINK SPACE); and then measured their size again with:

select sum(dbms_lob.getlength (lob_column_name)) from table_name;


To my complete surprise, the results were exactly the same as before the re-org/shrink. Not even 1 byte smaller.


Did I do anything wrong?


Thank you,


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Locked on Oct 14 2015
Added on Sep 15 2015
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