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ORA-29294 Raised When UTL_COMPRESS.LZ_UNCOMPRESS to decompress valid compressed data from a BLOB (Doc ID 1544982.1)

Last updated on JULY 25, 2022

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 10.1 to 11.2]
PL/SQL - Version to [Release 10.1 to 11.2]
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Information in this document applies to any platform.


Problem Description
I am running into an error when rusing utl_compress.lz_uncompress  to read and decompress compressed XML data from a BLOB column.

Ideally, I would be able to create PL/SQL code that uses utl_compress.lz_uncompress
  1. Read the LOB
  2. decompress it
  3. load it into an XML table -- without extracting the data to disk


 Attempts to read and uncompress the compressed XML using utl_compress.lz_uncompress, as shown in the below code, generates an error (error message follows PL/SQL code) during the uncompress operation.

The data in the BLOB column is a valid compressed file.

I am able to:

  1) extract the BLOB data through SQL Developer by double clicking on the (BLOB) column

      selecting "Download"  --  and uncompressing the saved file with any of 7-Zip, Winzip, or Windows based compressed folder,

  2) extracting the BLOB data with a java program and saving it to disk, then uncompressing with the previously mentioned tools.




Is this Oracle proprietary or known problem?


No known change : the problem appears to be server neutral and has reproduced using 11.2.x on various servers

Here is the example showing the problem





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