Database Reference
In-Depth Information
X$KFFXP
also contains the file number and incarnation. Since the view must keep track of
all the striped and mirrored extents, it includes a number of other columns that hold informa-
tion on disk groups, disks, and ASM files. Table 12-1 lists the columns of
X$KFFXP
.
Table 12-1.
X$KFFXP Columns
X$KFFXP Column Name
Meaning
ADDR
Address
INDX
Row index
INST_ID
Instance identifier (1 for single instance, 1..
n
for RAC)
GROUP_KFFXP
Disk group number; corresponds to
V$ASM_DISKGROUP.GROUP_NUMBER
NUMBER_KFFXP
File number; corresponds to
V$ASM_FILE.FILE_NUMBER
COMPOUND_KFFXP
Compound index; corresponds to
V$ASM_FILE.COMPOUND_INDEX
INCARN_KFFXP
Incarnation; corresponds to
V$ASM_FILE.INCARNATION
PXN_KFFXP
Unknown
XNUM_KFFXP
Extent number
LXN_KFFXP
Logical extent number (0=primary, 1=mirrored copy)
DISK_KFFXP
Disk number; corresponds to
V$ASM_DISK.DISK_NUMBER
AU_KFFXP
Offset within the device in multiples of the allocation unit size
(
V$ASM_DISKGROUP.ALLOCATION_UNIT_SIZE
)
FLAGS_KFFXP
Unknown
CHK_KFFXP
Unknown
Salvaging an SPFILE
Presumably I am not the only DBA who has had to face the issue of a server parameter file
(
SPFILE
) that had undergone a modification with
ALTER
SYSTEM
, which rendered the file unsuitable
to start up an instance. This may manifest itself by several different errors. Here is one example:
SQL> STARTUP
ORA-00821: Specified value of sga_target 356M is too small, needs to be at least
564M
ORA-01078: failure in processing system parameters
The
SPFILE
, which is a binary file, cannot be modified, except by performing an
ALTER
SYSTEM
command against a running instance. However, in this case the instance refuses to start
up with the
SPFILE
. If the
SPFILE
is stored in a file system, it can easily be converted to a text
parameter file with a text editor by removing non-ASCII characters. However, if the
SPFILE
is an
ASM file and you do not have a recent RMAN backup of it, you are stuck. Unless, of course, you
know how to retrieve the
SPFILE
directly from an ASM disk, which is what you will learn shortly.