[20141106]type and table.txt
--看看建立type与表.
SCOTT@test> @ver1
PORT_STRING VERSION BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx 11.2.0.3.0 Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
CREATE OR REPLACE TYPE SCOTT.ty_obj as object
(
output varchar2(250)
);
/
SCOTT@test> CREATE TABLE TX OF TY_OBJ;
Table created.
SCOTT@test> select * from dba_tables where table_name='TX' and owner=user;
no rows selected
--竟然无法查询.
SCOTT@test> select owner,table_name,tablespace_name from dba_all_tables where table_name='TX' and owner=user;
OWNER TABLE_NAME TABLESPACE_NAME
------ ---------- ------------------------------
SCOTT TX USERS
SCOTT@test> @ddl scott.tx
C100
----------------------------------------------------------------------------
CREATE TABLE "SCOTT"."TX" OF "SCOTT"."TY_OBJ"
OIDINDEX ( PCTFREE 10 INITRANS 2 MAXTRANS 255
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "USERS" )
PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255
NOCOMPRESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "USERS" ;
SCOTT@test> select column_name,data_type,column_id,hidden_column,virtual_column,segment_column_id,internal_column_id,data_default c30 from dba_tab_cols where owner=user and table_name='TX';
COLUMN_NAME DATA_TYPE COLUMN_ID HID VIR SEGMENT_COLUMN_ID INTERNAL_COLUMN_ID C30
-------------------- ---------- ---------- --- --- ----------------- ------------------ ------------------------------
SYS_NC_OID$ RAW YES NO 1 1 SYS_OP_GUID()
SYS_NC_ROWINFO$ TY_OBJ YES YES 2
OUTPUT VARCHAR2 1 NO NO 2 3
--可以发现仅仅显示OUTPUT,在段中保存SYS_NC_OID$,OUTPUT.SYS_NC_OID$的缺省值SYS_OP_GUID(),guid的串.好像随机生产的串,冲突的概率很低.
--如何插入呢?
SCOTT@test> insert into tx (output) values ('this is a test!');
1 row created.
SCOTT@test> select * from tx;
OUTPUT
-----------------------------
this is a test!
SCOTT@test> select SYS_NC_OID$ c40 ,SYS_NC_ROWINFO$ c50 ,OUTPUT c20 from tx ;
C40 C50(OUTPUT) C20
---------------------------------------- -------------------------------------------------- --------------------
0727ECBEB9CB37C2E0532864A8C0A4BF TY_OBJ('this is a test!') this is a test!
SCOTT@test> select TY_OBJ('aaa') c20 from dual ;
C20(OUTPUT)
--------------------
TY_OBJ('aaa')
SCOTT@test> select SYS_OP_GUID() from dual ;
SYS_OP_GUID()
--------------------------------
0727ECBEB9CC37C2E0532864A8C0A4BF
--看看块内存储:
SCOTT@test> select rowid,SYS_NC_OID$ c40 ,SYS_NC_ROWINFO$ c50 ,OUTPUT c20 from tx ;
ROWID C40 C50(OUTPUT) C20
------------------ ---------------------------------------- -------------------------------------------------- --------------------
AABHdYAAEAAAAcDAAA 0727ECBEB9CB37C2E0532864A8C0A4BF TY_OBJ('this is a test!') this is a test!
SCOTT@test> @lookup_rowid AABHdYAAEAAAAcDAAA
OBJECT FILE BLOCK ROW DBA TEXT
---------- ---------- ---------- ---------- -------------------- ----------------------------------------
292696 4 1795 0 4,1795 alter system dump datafile 4 block 1795;
--bbed 观察:
BBED> set dba 4,1795
DBA 0x01000703 (16779011 4,1795)
BBED> p *kdbr[0]
rowdata[0]
----------
ub1 rowdata[0] @8152 0x2c
BBED> x /rxc
rowdata[0] @8152
----------
flag@8152: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@8153: 0x01
cols@8154: 2
col 0[16] @8155: 0x07 0x27 0xec 0xbe 0xb9 0xcb 0x37 0xc2 0xe0 0x53 0x28 0x64 0xa8 0xc0 0xa4 0xbf
col 1[15] @8172: this is a test!
