Unique system index on a blob column in a partitioned table

Hi,

I have a table

CREATE TABLE "owner"."table_name"

   (     "id1" NUMBER(5,0) NOT NULL ENABLE,

        "id2" NUMBER(19,0) NOT NULL ENABLE,

       "SAMPLES" BLOB,

       CONSTRAINT "PK_tablename" PRIMARY KEY ("id1", "id2")

       USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255

....

STORAGE(

  BUFFER_POOL DEFAULT)

  TABLESPACE "tablespacename"

LOB ("SAMPLES") STORE AS (

  ENABLE STORAGE IN ROW CHUNK 16384 PCTVERSION 10

  NOCACHE LOGGING

  STORAGE(

  BUFFER_POOL DEFAULT))

  PARTITION BY RANGE ("id1","id2")

(PARTITION "tablename_1_43601"  VALUES LESS THAN (1, 5001)

  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255

......

}

SELECT * FROM USER_INDEXES WHERE .....;

SYS_IL0001531233C00003$$

LOB

OWNER

TABLE_NAME

TABLE

UNIQUE

This is a system generated index, it seems oracle create a LOCAL unique index on the blob column?