After HCC Compression (Query Low). The first stats gather is taking too long. Is that expected?

Engineered Systems : Exadata

Database version: 12.1.0.2

Table size: 1TB (Before Compression) , 150GB (After Compression)

No's of Indexes: 4

First time Stats gather after Compression: 15 hrs

Stats query:

BEGIN

  DBMS_STATS.GATHER_TABLE_STATS

   (ownname => '<SCHEMA>',

    tabname => '<TABLE_NAME>',

    cascade => TRUE,

    estimate_percent => 100,                    <<< Tried with Auto on another table with same size, that is also took 12+ hrs.

    method_opt => 'FOR ALL INDEXED COLUMNS SIZE AUTO',

    degree => 72);

END;