v$type 简单记录
v$type_size 对理解 block structure 很有用，简单记录一下
_sys@DAVID> select * from V$TYPE_SIZE ;COMPONEN TYPE DESCRIPTION TYPE_SIZE-------- -------- -------------------------------- ----------S EWORD EITHER WORD 4S EB1 EITHER BYTE 1 1S EB2 EITHER BYTE 2 2S EB4 EITHER BYTE 4 4S UWORD UNSIGNED WORD 4S UB1 UNSIGNED BYTE 1 1S UB2 UNSIGNED BYTE 2 2S UB4 UNSIGNED BYTE 4 4S SWORD SIGNED WORD 4S SB1 SIGNED BYTE 1 1S SB2 SIGNED BYTE 2 2S SB4 SIGNED BYTE 4 4S BOOLEAN BOOLEAN 4S FLOAT FLOAT 4S DOUBLE DOUBLE 8S SIZE_T SIZE_T 8S DSIZE_T DSIZE_T 4S PTR_T PTR_T 8K KDBA DATABASE BLOCK ADDRESS 4K KTNO TABLE NUMBER IN CLUSTER 1K KSCN SYSTEM COMMIT NUMBER 8K KXID TRANSACTION ID 8K KUBA UNDO ADDRESS 8KCB KCBH BLOCK COMMON HEADER 20KTB KTBIT TRANSACTION VARIABLE HEADER 24KTB KTBBH TRANSACTION FIXED HEADER 48KTB KTBBH_BS TRANSACTION BLOCK BITMAP SEGMENT 8KDB KDBH DATA HEADER 14KDB KDBT TABLE DIRECTORY ENTRY 4KTE KTECT EXTENT CONTROL 44KTE KTECH EXTENT CONTROL 72KTE KTETB EXTENT TABLE 8KTS KTSHC SEGMENT HEADER 8KTS KTSFS SEGMENT FREE SPACE LIST 20KTS KTSPHW PAGE TABLE SEGMENT HWM 60KTS KTSPHC PAGE TABLE SEGMENT HEADER 112KTS KTSPFHC LEVEL 1 BITMAP BLOCK HEADER 184KTS KTSPSHC LEVEL 2 BITMAP BLOCK HEADER 96KTS KTSPTHC LEVEL 3 BITMAP BLOCK HEADER 88KTU KTUBH UNDO HEADER 16KTU KTUXE UNDO TRANSACTION ENTRY 40KTU KTUXC UNDO TRANSACTION CONTROL 104KDX KDXCO INDEX HEADER 16KDX KDXLE INDEX LEAF HEADER 32KDX KDXBR INDEX BRANCH HEADER 2445 rows selected.
