Database Reference
In-Depth Information
Applying the procedure for making sense out of cryptic X$ column names from the previous
chapter yields the column mapping between
GV$BH
and
X$BH
shown in Table 10-1. Note that
only a subset of
X$BH
columns, which includes all columns of
GV$BH
, is shown. Approximately
half of the columns in
X$BH
are not externalized by
GV$BH
. Table 10-1 contains n/a under the
heading “GV$BH Column Name” for columns not externalized by
GV$BH
.
Table 10-1.
Mapping of GV$BH Columns to X$BH
X$BH Column Name
GV$BH Column Name
Meaning
ADDR
n/a
Buffer header address
INDX
n/a
Buffer header index (0-n)
INST_ID
INST_ID
Instance number, corresponds to
GV$INSTANCE.INSTANCE_NUMBER
HLADDR
n/a
Child latch address
BLSIZ
n/a
Block size
FLAG
DIRTY
,
TEMP
,
PING
,
STALE
,
DIRECT
Flag for the type and status of
the block
TS#
TS#
Tablespace number; corresponds to
V$TABLESPACE.TS#
FILE#
FILE#
File number; corresponds to
V$DATAFILE.FILE#
DBARFIL
n/a
Relative file number
DBABLK
BLOCK#
Block number from data block
address
CLASS
CLASS#
Class number
STATE
STATUS
Block status (free, xcur, cr, etc.)
LE_ADDR
LOCK_ELEMENT_ADDR
Lock element address
OBJ
OBJD
Dictionary object number of the
segment that contains the object
CR_SCN_BAS
n/a
Consistent read SCN base
CR_SCN_WRP
n/a
Consistent read SCN wrap
TCH
n/a
touch count
TIM
n/a
touch time
