some cr v$bh rows are duplicates

v$bh has no PRIMARY KEY.
Duplicate ROWS are possible.

SQL> DESC v$bh
 Name                                                                                                              NULL?    TYPE
 ----------------------------------------------------------------------------------------------------------------- -------- ----------------------------------------------------------------------------
 FILE#                                                                                                                      NUMBER
 BLOCK#                                                                                                                     NUMBER
 CLASS#                                                                                                                     NUMBER
 STATUS                                                                                                                     VARCHAR2(10)
 XNC                                                                                                                        NUMBER
 FORCED_READS                                                                                                               NUMBER
 FORCED_WRITES                                                                                                              NUMBER
 LOCK_ELEMENT_ADDR                                                                                                          RAW(8)
 LOCK_ELEMENT_NAME                                                                                                          NUMBER
 LOCK_ELEMENT_CLASS                                                                                                         NUMBER
 DIRTY                                                                                                                      VARCHAR2(1)
 TEMP                                                                                                                       VARCHAR2(1)
 PING                                                                                                                       VARCHAR2(1)
 STALE                                                                                                                      VARCHAR2(1)
 DIRECT                                                                                                                     VARCHAR2(1)
 NEW                                                                                                                        CHAR(1)
 OBJD                                                                                                                       NUMBER
 TS#                                                                                                                        NUMBER
 LOBID                                                                                                                      NUMBER
 CACHEHINT                                                                                                                  NUMBER
 FLASH_CACHE                                                                                                                VARCHAR2(7)
 CELL_FLASH_CACHE                                                                                                           VARCHAR2(7)
 CON_ID                                                                                                                     NUMBER

SQL> SELECT COUNT(*)
  2  FROM v$bh WHERE FILE#=3 AND BLOCK#=4954 AND status = 'cr'
  3  ;

  COUNT(*)
----------
         7

SQL> SELECT COUNT(*)
  2  FROM
  3  (
  4  SELECT DISTINCT
  5          FILE#,
  6          BLOCK#,
  7          CLASS#,
  8          STATUS,
  9          XNC,
 10          FORCED_READS,
 11          FORCED_WRITES,
 12          LOCK_ELEMENT_ADDR,
 13          LOCK_ELEMENT_NAME,
 14          LOCK_ELEMENT_CLASS,
 15          DIRTY,
 16          TEMP,
 17          PING,
 18          STALE,
 19          DIRECT,
 20          NEW,
 21          OBJD,
 22          TS#,
 23          LOBID,
 24          CACHEHINT,
 25          FLASH_CACHE,
 26          CELL_FLASH_CACHE,
 27          CON_ID
 28  FROM v$bh WHERE FILE#=3 AND BLOCK#=4954 AND status = 'cr'
 29  );

  COUNT(*)
----------
         1

Here, explicitly, are 7 duplicate v$bh ROWS.

SELECT * FROM v$bh
WHERE FILE#=3 AND BLOCK#=4954 AND status = 'cr';

FILE#   BLOCK#  CLASS#  STATUS  XNC FORCED_READS    FORCED_WRITES   LOCK_ELEMENT_ADDR   LOCK_ELEMENT_NAME   LOCK_ELEMENT_CLASS
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00
3   4954    8   cr  0   0   0   00

DIRTY   TEMP    PING    STALE   DIRECT  NEW OBJD    TS# LOBID   CACHEHINT   FLASH_CACHE CELL_FLASH_CACHE    CON_ID
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1
N   N   N   N   N   N   8107    1   0   15  DEFAULT DEFAULT 1

No duplicate ROWS exist IN x$bh

SQL> SELECT COUNT(*)
  2  FROM x$bh x
  3  WHERE x.obj = 8107
  4  AND x.dbablk = 4954
  5  AND x.state = 3;

  COUNT(*)
----------
         7

Ix x$bh, the ROWS are different BY ADDR, INDX, OR SCN

SQL> SELECT x.addr, x.indx, x.con_id, x.dbarfil, x.dbablk, x.obj, cr_scn_bas, cr_scn_wrp, x.state
  2  FROM x$bh x
  3  WHERE x.obj = 8107
  4  AND x.dbablk = 4954
  5  AND x.state = 3
  6  ORDER BY x.con_id, x.dbarfil, x.dbablk, x.obj, cr_scn_bas, cr_scn_wrp;

ADDR                   INDX     CON_ID    DBARFIL     DBABLK        OBJ CR_SCN_BAS CR_SCN_WRP      STATE
---------------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
00007F7BF89DDCA8       2518          1          3       4954       8107   31303060          0          3
00007F7BF89DDE00       2517          1          3       4954       8107   31304429          0          3
00007F7BF89DE420       2516          1          3       4954       8107   31304438          0          3
00007F7BF89DE578       2515          1          3       4954       8107   31304853          0          3
00007F7BF89DE6D0       2514          1          3       4954       8107   31304862          0          3
00007F7BF89DE828       2513          1          3       4954       8107   31305577          0          3
00007F7BF89DEAD8       2511          1          3       4954       8107   31305585          0          3

7 ROWS selected.