如何對錶手工擴充套件一個extent或多個extent

用alter table allocate extent 命令來實現

SQL> show user
USER is "SYS"

SQL> create table test_extent(a number,b varchar2(10)); ===============> table created

Table created.

SQL> select OWNER,SEGMENT_NAME,SEGMENT_TYPE,EXTENT_ID from dba_extents where segment_name='TEST_EXTENT'; ==============> Checked the extents

OWNER SEGMENT_NAME SEGMENT_TYPE EXTENT_ID
---------- -------------------- ------------------ ----------
SYS TEST_EXTENT TABLE 0

SQL> alter table test_extent allocate extent; =============================> added an extent

Table altered.

SQL> select OWNER,SEGMENT_NAME,SEGMENT_TYPE,EXTENT_ID from dba_extents where segment_name='TEST_EXTENT'; =====> Adds one extent only

OWNER SEGMENT_NAME SEGMENT_TYPE EXTENT_ID
---------- -------------------- ------------------ ----------
SYS TEST_EXTENT TABLE 0
SYS TEST_EXTENT TABLE 1

SQL> alter table test_extent allocate extent(size 5m); ==============================> This will add multiple extents in a single alter statement

Table altered.

SQL> select OWNER,SEGMENT_NAME,SEGMENT_TYPE,EXTENT_ID from dba_extents where segment_name='TEST_EXTENT'; =====> Multiple extents added

OWNER SEGMENT_NAME SEGMENT_TYPE EXTENT_ID
---------- -------------------- ------------------ ----------
SYS TEST_EXTENT TABLE 0
SYS TEST_EXTENT TABLE 1
SYS TEST_EXTENT TABLE 2
SYS TEST_EXTENT TABLE 3
SYS TEST_EXTENT TABLE 4
SYS TEST_EXTENT TABLE 5
SYS TEST_EXTENT TABLE 6

7 rows selected.

如何對錶手工擴充套件一個extent或多個extent

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