Oracle Deep Internal 3 (ver.2)
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1. The document describes how Oracle allocates CU blocks and CR blocks in the buffer cache when updating column values from A to I through consecutive commits. 2. It shows the expected outcome of 6 CR blocks being allocated for the 6 updates before a new CU block is needed. 3. Using a tool to view the internal Oracle buffer cache, it demonstrates this expected behavior, showing the CR blocks and CU blocks allocated for updates from A to I.
![© Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved.
Scenario
Buffer Cache
XCURRENT
col 1: [ 1] 41 (A)
BH
(0x657d8238)
B
A
C
D
E
F
G
H
I
Update; Commit
Update;Commit
BCDEFGHI
When update a value ‘A’ with values ‘B’ to ‘I’ consecutively,
How are CU blocks and CR blocks allocated inside the Buffer Cache?](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Oracle Deep Internal 3 (ver.2)
- 2. © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Scenario Buffer Cache XCURRENT col 1: [ 1] 41 (A) BH (0x657d8238) B A C D E F G H I Update; Commit Update;Commit BCDEFGHI When update a value ‘A’ with values ‘B’ to ‘I’ consecutively, How are CU blocks and CR blocks allocated inside the Buffer Cache?
- 3. © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Expected outcome Buffer Cache CURRENT BLOCK (XCUR) Update S1 Consistent Read Block (CR 1)& UNDO Update S2 Consistent Read Block (CR 2)& UNDO Update S3 Consistent Read Block (CR 3)& UNDO Update S4 Consistent Read Block (CR 4)& UNDO Update S5 Consistent Read Block (CR 5)& UNDO Update S6
- 4. © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. 2013, Oracle 10g Performance: chapter 06 buffer cache 25,26 page, Kyle Hailey Cited from http://www.slideshare.net/khailey/oracle-10g-performance-chapter-06-buffer-cache It's so difficult to understand only through the book. I'd like to check internal actual situation of oracle with my own eyes “Max length in Cache Buffer”mechanism as explained in Kyle Hailey's presentation 1. UPDATE T1 SET C2= 'B' ; COMMIT ; 2. UPDATE T1 SET C2= 'C' ; COMMIT ; 3. UPDATE T1 SET C2= 'D' ; COMMIT ; . . . . . . 9. UPDATE T1 SET C2= 'G' ; COMMIT ; . . . . . . ?
- 5. © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Inside of Oracle via ODI Analyzer When _db_block_max_cr_dba = 6 Buffer Cache CR col 1: [ 1] 41 (A) BH (0x657d8238) CR col 1: [ 1] 42 (B) BH (0x657d8100) CR col 1: [ 1] 43 (C) BH (0x653fab88) CR col 1: [ 1] 44 (D) BH (0x653fa7e0) CR col 1: [ 1] 45 (E) BH (0x653fa438) CR col 1: [ 1] 46 (F) BH (0x653fa090) New CU block New CU block New CU Block XCURRENT XCURRENTXCURRENT XCURRENT XCURRENT New CU Block XCURRENT col 1: [ 1] 49 (I) XCURRENT block 1 block 2 block 3 block 4 block 5 block 6 block 1 block 2 block 3 New CU block XCURRENT col 1: [ 1] 47 (G) CR col 1: [ 1] 47 (G) XCURRENT col 1: [ 1] 48 (H) CR col 1: [ 1] 48 (H) CR Block Reuse CR Block Reuse CR Block Reuse Oracle init parameter When _db_block_max_cr_dba = 6
- 6. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block 1. UPDATE T1 SET C2= ' B ' ; COMMIT ; Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 2 “A” “B” “A” UPDATE T1 SET c2 = ‘B’
- 7. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block 2. UPDATE SYSTEM.T1 SET C2= ' C ' ; COMMIT ; Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” “A” UPDATE T1 SET c2 = ‘C’ BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C”
- 8. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block 3. UPDATE SYSTEM.T1 SET C2= ' D ' ; COMMIT ; Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” UPDATE T1 SET c2 = ‘D’
- 9. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block 4. UPDATE SYSTEM.T1 SET C2= ' E ' ; COMMIT ; Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” BH (0x653fa1c8) file#: 6 rdba: 0x01800112 (6/274) class: 104 ba: 0x653b6000 xid: 0x002c.001.000000c4 seq: 0x69 * Rec #0x11 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 44 “D” BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 BH (0x653fa438) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653ba000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 ---- 1 fsc 0x0000.00000000 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 45 5 “E” UPDATE T1 SET c2 = ‘E’
- 10. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block 5. UPDATE SYSTEM.T1 SET C2= ' F ' ; COMMIT ; Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” BH (0x653fa1c8) file#: 6 rdba: 0x01800112 (6/274) class: 104 ba: 0x653b6000 xid: 0x002c.001.000000c4 seq: 0x69 * Rec #0x11 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 44 “D” BH (0x653f9e20) file#: 6 rdba: 0x01800102 (6/258) class: 102 ba: 0x653b0000 xid: 0x002b.001.000000c6 seq: 0x62 * Rec #0x2 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 45 “E” BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” BH (0x653fa438) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653ba000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 --U- 1 fsc 0x0000.0021a127 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 45 5 “E” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 BH (0x653fa090) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653b4000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 46 6 “F” UPDATE T1 SET c2 = ‘F’
- 11. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 “A” 6. UPDATE SYSTEM.T1 SET C2= ' G ' ; COMMIT ; Reuse BH ‘8283’ Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 --U- 1 fsc 0x0000.0021a12d 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 C--- 0 scn 0x0000.0021a12a tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 47 1 “G” “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” BH (0x653fa1c8) file#: 6 rdba: 0x01800112 (6/274) class: 104 ba: 0x653b6000 xid: 0x002c.001.000000c4 seq: 0x69 * Rec #0x11 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 44 “D” BH (0x653f9e20) file#: 6 rdba: 0x01800102 (6/258) class: 102 ba: 0x653b0000 xid: 0x002b.001.000000c6 seq: 0x62 * Rec #0x2 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 45 “E” BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” BH (0x653f9bb0) file#: 6 rdba: 0x018000f2 (6/242) class: 100 ba: 0x653ac000 xid: 0x002a.001.000000c6 seq: 0x62 * Rec #0x3 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 46 “F” BH (0x653fa438) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653ba000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 --U- 1 fsc 0x0000.0021a127 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 45 5 “E” BH (0x653fa090) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653b4000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 46 6 “F” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 UPDATE T1 SET c2 = ‘G’
- 12. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 “A” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” 7. UPDATE SYSTEM.T1 SET C2= ' H ' ; COMMIT ; Reuse BH ‘8100’ Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 sst: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 C--- 0 scn 0x0000.0021a12d 0x02 0x0029.001.00000107 0x018000e2.00bc.04 --U- 1 fsc 0x0000.0021a130 0x03 0x002b.001.000000c6 0x01800102.0062.02 C--- 0 scn 0x0000.0021a12a tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 48 2 “H” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” BH (0x653fa1c8) file#: 6 rdba: 0x01800112 (6/274) class: 104 ba: 0x653b6000 xid: 0x002c.001.000000c4 seq: 0x69 * Rec #0x11 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 44 “D” BH (0x653f9e20) file#: 6 rdba: 0x01800102 (6/258) class: 102 ba: 0x653b0000 xid: 0x002b.001.000000c6 seq: 0x62 * Rec #0x2 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 45 “E” BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” BH (0x653f9bb0) file#: 6 rdba: 0x018000f2 (6/242) class: 100 ba: 0x653ac000 xid: 0x002a.001.000000c6 seq: 0x62 * Rec #0x3 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 46 “F” BH (0x653fa438) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653ba000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 --U- 1 fsc 0x0000.0021a127 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 45 5 “E” BH (0x653fa090) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653b4000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 46 6 “F” BH (0x653f9940) file#: 6 rdba: 0x018000e2 (6/226) class: 98 ba: 0x653a8000 xid: 0x0029.001.00000107 seq: 0xbc * Rec #0x4 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 47 “G” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 --U- 1 fsc 0x0000.0021a12d 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 C--- 0 scn 0x0000.0021a12a tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 47 1 “G” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 UPDATE T1 SET c2 = ‘H’
- 13. Buffer Cache © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Undo Segment Data Block BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 1 “A” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 ---- 1 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 42 2 “B” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0027.000.000000c4 0x00000000.0000.00 C--- 0 scn 0x0000.0021a110 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 43 3 “C” 8. UPDATE SYSTEM.T1 SET C2= ' I ' ; COMMIT ; Reuse BH‘ab88’ Rows block_row_dump: tab 0, row 0, @0x1f70 tl: 16 fb: --H-FL-- lb: 0x0 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 41 “A” BH (0x657d7e90) file#: 6 rdba: 0x018000a2 (6/162) class: 90 ba: 0x65434000 xid: 0x0025.000.00000138 seq: 0x9b * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 41 “A” BH (0x653fa918) file#: 6 rdba: 0x01800092 (6/146) class: 86 ba: 0x653c2000 xid: 0x0023.000.00000132 seq: 0xa2 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 42 “B” BH (0x653fa570) file#: 6 rdba: 0x01800082 (6/130) class: 18 ba: 0x653bc000 xid: 0x0001.000.000009ef seq: 0x352 * Rec #0x1 slt: 0x00 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 43 “C” BH (0x653fab88) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c6000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 C--- 0 scn 0x0000.0021a12d 0x02 0x0029.001.00000107 0x018000e2.00bc.04 C--- 0 scn 0x0000.0021a130 0x03 0x0028.004.000000db 0x018000d3.00b2.08 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 49 3 “I” BH (0x653fa1c8) file#: 6 rdba: 0x01800112 (6/274) class: 104 ba: 0x653b6000 xid: 0x002c.001.000000c4 seq: 0x69 * Rec #0x11 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 44 “D” BH (0x653f9e20) file#: 6 rdba: 0x01800102 (6/258) class: 102 ba: 0x653b0000 xid: 0x002b.001.000000c6 seq: 0x62 * Rec #0x2 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 45 “E” BH (0x653fa7e0) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653c0000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 ---- 1 fsc 0x0000.00000000 0x02 0x0025.000.00000138 0x018000a2.009b.01 C--- 0 scn 0x0000.0021a11e 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 44 4 “D” BH (0x653f9bb0) file#: 6 rdba: 0x018000f2 (6/242) class: 100 ba: 0x653ac000 xid: 0x002a.001.000000c6 seq: 0x62 * Rec #0x3 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 46 “F” BH (0x653fa438) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653ba000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 --U- 1 fsc 0x0000.0021a127 0x03 0x0023.000.00000132 0x01800092.00a2.01 C--- 0 scn 0x0000.0021a121 tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 45 5 “E” BH (0x653fa090) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x653b4000 st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.000.000009ef 0x01800082.0352.01 C--- 0 scn 0x0000.0021a124 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 ---- 1 fsc 0x0000.00000000 tl: 16 fb: --H-FL-- lb: 0x3 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 46 6 “F” BH (0x653f9940) file#: 6 rdba: 0x018000e2 (6/226) class: 98 ba: 0x653a8000 xid: 0x0029.001.00000107 seq: 0xbc * Rec #0x4 slt: 0x01 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 47 “G” BH (0x657d8238) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x6543a000 st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 --U- 1 fsc 0x0000.0021a12d 0x02 0x002c.001.000000c4 0x01800112.0069.11 C--- 0 scn 0x0000.0021a127 0x03 0x002b.001.000000c6 0x01800102.0062.02 C--- 0 scn 0x0000.0021a12a tl: 16 fb: --H-FL-- lb: 0x1 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 47 1 “G” BH (0x653f96d0) file#: 6 rdba: 0x018000d3 (6/211) class: 96 ba: 0x653a4000 xid: 0x0028.004.000000db seq: 0xb2 * Rec #0x8 slt: 0x04 objn: 69880(0x000110f8) * Layer: 11 (Row) opc: 1 rci 0x00 col 1: [ 1] 48 “H” BH (0x657d8100) file#: 5 rdba: 0x0140dcab (5/56491) class: 1 ba: 0x65438000 sst: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x002a.001.000000c6 0x018000f2.0062.03 C--- 0 scn 0x0000.0021a12d 0x02 0x0029.001.00000107 0x018000e2.00bc.04 --U- 1 fsc 0x0000.0021a130 0x03 0x002b.001.000000c6 0x01800102.0062.02 C--- 0 scn 0x0000.0021a12a tl: 16 fb: --H-FL-- lb: 0x2 cc: 2 col 0: [10] 31 20 20 20 20 20 20 20 20 20 col 1: [ 1] 48 2 “H” st: CR md: NULL fpin: 'kdswh11: kdst_fetch' tch: 1 UPDATE T1 SET c2 = ‘I’
- 14. © Copyrights 2001~2016, EXEM CO.,LTD. All Rights Reserved. Inside of Oracle via ODI tool When _db_block_max_cr_dba = 6 Buffer Cache CR col 1: [ 1] 41 (A) BH (0x657d8238) CR col 1: [ 1] 42 (B) BH (0x657d8100) CR col 1: [ 1] 43 (C) BH (0x653fab88) CR col 1: [ 1] 44 (D) BH (0x653fa7e0) CR col 1: [ 1] 45 (E) BH (0x653fa438) CR col 1: [ 1] 46 (F) BH (0x653fa090) New CU block New CU block New CU Block XCURRENT XCURRENTXCURRENT XCURRENT XCURRENT New CU Block XCURRENT col 1: [ 1] 49 (I) XCURRENT CR Block Reuse CR Block Reuse bloc k1 bloc k2 bloc k3 block 4 block 5 block 6 block 1 block 2 block 3 New CU block CR Block Reuse XCURRENT col 1: [ 1] 47 (G) CR col 1: [ 1] 47 (G) XCURRENT col 1: [ 1] 48 (H) CR col 1: [ 1] 48 (H) When _db_block_max_cr_dba equals 6, a maximum of 6 data blocks are allocated and rotate among them for updates.
- 15. Oracle Deep Internal Blog Video E-mail NAVER http://cafe.naver.com/playexem ITPUB http://blog.itpub.net/31135309/ Wordpress https://playexem.wordpress.com/ Slideshare http://www.slideshare.net/playexem Youtube https://www.youtube.com/channel/UC 5wKR_-A0eL_Pn_EMzoauJg Research & Contents Team Sook jin, Kim edu@ex-em.com For more information, or to schedule an on-site education, contact via blog or e-mail