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There is coordinate data which is stored in a BLOB, similar to the arcgis ST_GEOMETRY type of points. The storage contains the byte stream of the point coordinates that define the geometry like this:

Hex dump of a blob

How can I get the data from the BLOB in Oracle?

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Shuai Ma
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  • "similar to the arcgis ST_GEOMETRY type of points" Well, is it ArcGIS ST_GEOMETRY? If so, you probably need to use an ArcGIS client to read the data. If it's only "similar" to ST_GEOMETRY, then I'm not sure what you would do. – Gary Sheppard Oct 19 '17 at 14:47

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BLOBs are binary data. They could contain literally anything. Oracle has no built-in mechanism for extracting data from a BLOB. Your options are:

  1. Whatever part of your application wrote the binary data should be responsible for unpacking and displaying the data.
  2. Write some PL/SQL to retrieve the data using UTL_RAW functions to work with binary data. Find out more Doing this requires you to understand how the program which wrote the binary structured it.

This is why storing data in binary is usually a bad idea. Sure, you save space but essentially this obfuscates the data and imposes a toll on using it. If storage is that much of an issue consider compression instead.

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