Karpova_bazy_dannyh
.pdf
183



. 


































(





).
184 |
9. |















.







, 



















































. 





















.



.
















.






























.




























.











, 





















-





, 


















.
, 



,
-
























, 









-


































-

.


















, 












(

















) 





















. 

, 















, 




,
- 












, 














-


















.


















, 












-




















, 










-


.
|
|
- |
, |
, |
- |
|
. |
- |
|
. |
- |
, |
, |
|
. |
, |
|



. 




























-








, 
























-











.

































,

-






. 

















, 






186 |
9. |
2 





:





.





























, 






-






EXTENTSIZE 










, NEXT SIZE -



-










.













, 













4 



, 





2 


.
|
|
- |
, |
. |
- |















, 
















.




















. 


















.
, |
, |
- |
, |
|
- |





.















: 

















-











, 


16, 















16 
-


.



, 











16 

, 







16 




|
32 |
. |
|
|
|
- |
(Ebl- |
space). |
|
|
|
|
: |
, |
, |
blob- |
. Blob- |
Binary Lang Object, |
|
|
. |
|
- |
Memo. |
|
|
- |
, |
, |
|
. |
, |
|
, |
|
















, 

















.





















(

-

) 





-



. 













. 









: 



















, 

















-










.





















, 








. 9.13.



4-





, 2 


















-


2 








. 
























. 














255 

. 





-


, 


Row ID - 




, 





4




. 




187
3

, 
























16. 777.215 

-
.








(24 

)

. 9.13. 









, 
















.




























, 






-





. 

, 














, 




(

-

) 


























-



«

» (








), 





















.

















-


. 


blob 





















,


, 









, 




. 






























, 





















.


.
2-




4-





. 4-


























Varchar, Byte, Text, 

















2-






.













32 


. 



















4-






. 

i-










i-




. 
-







1-

































.
|
|
- |
, |
, |
- |
, |
. |
- |
|
|
, |
|
, |
- |
|
. |
|
|
|
. |
|
, |
- |
|
, |
- |








.
188 |
9. |



MS SQL 6.5



6.0
6.5 MS SQL Server 






























[1]. 























-








(DEVICE), 








. 









256 




. 












MASTER, 








- 





Master Model, Pubs, TempDb. 



Master 




0 

.
|
|
|
, |
16 777 216 |
|
|
2 |
|
|
(Virtual page), |
|
|
|
32 |
. |
4 |
|
|
«Master» |
|
|
|
(Configuration block) |
|
- |
|
|
|
|
|
. |
|
|
|
|
|
. |
|
|
|
|
, |
|
|
|
|
|
|
|
. |
|
|
|
|
|
|
|
|
. |
|
|
|
|
|
3 |
. |
|
: |
|
|
|
|
, |
|
|
|
|
|
|
|
|
(extent) 16 |
8 |
|
|
|
, |
|
|
|
|
(Allocation Unit) |
512 |
32 |
|
|
|
|
(256 |
). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
- |
|
. |
|
|
|
|
|
1 |
, |
|
2 |
|
|
. |
|
|
|
|






:









(Allocation page),







(Data page);









(Index page),









(Text/image page), 










(Distribution page).














, 



32 

. 














, 
















,






























. 









, 


















.

. 





, 








256, 



0, 












.


, 












. 











32 16 







, 








. 




















:







,
189
|
, |
|
|
, |
|
|
(Allocation bitmap), |
|
|
(Deallocation bitmap), |
|
( |
), |
, |



.






























, 

















, 





. 





1, 

















, 
0 








.





























, 



-















. 


















- 










(



) 



. 




, 



-
|
|
|
|
|
|
|
|
|
|
|
|
, |
. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
- |
. |
, |
|
|
|
|
|
|
|
|
|
1 |
16 |
, |
|
. |
|
|
||||||||
|
|
|
|
|
|
|
|
|
|
|
. |
|
|
|
: |
, |
|
||||||||
( |
. |
. 9.14). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
32 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2048 |
|
|
|
|
|
|
|
|
|
2018 |
- |
|
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
|
|
|
|
|
|
|
- |
|
|
|
|
|
|
|
|
|
|
|
|
1962 |
- |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|

. 9.14. 












MS SQL Server 6.5























, 




















. 





2048 
, 32 







-


. 



, 













2 












, 












, 










-















.


















(


). 








































.



































.










, 





















- 







(











, 



190 |
|
|
9. |
|
|
NULL). |
, |
|
, |
, |
|
|
256, |
|
|
|
250 |
. |
- |
|
|
9.15. |
|
|
- |
|
- |
- |
|
( 1 |
) |
( 2 |
) |
|
. 9.15. |
MS SQL Server 6.5. |
|
|
, |
|
|
, |
. |
|
|
|
(Column offset table) |
: |
|
|
(Onset table adjust bytes) |
1 |
- |
|
, |
256 |
1 |
, |
|
, |
|
|
|
(1 |
|
|

).




































-







.
|
|
|
|
(Row |
|
offset table). |
|
|
|
|
- |
2 |
|
( |
. |
. 9.16). |
|
|
, SQL Server |
|
|
, |
|
|
|
. |
|
, |
- |
|
|
. |
|
|
|
|
|
. |
|
. 9.16 |
- |
, |
1 4 |
. |
|
|
|
|
|
. |
|
|
|
|
|
, |
1 |
. |
- |




SQL Server 






















, 




















, 














-


















.
SQL Server 6.5 


















. 



, 


-













,
191

, 

















. 


(






)
-






























. 



-























, 



















(Bll-factor). 









, 


























, 








.
0 




32 


0 49 


2 65 


3 83 


4
| |
| 83 |
| 0 |
| 65 | |
49 | |
0 |
|32 |
|
5 |
4 |
3 |
2 |
1 |
0 |

. 9.16. 






































.
Next 
Image.



(
. 
. 9.17). 

























-





















. 












-



,











.
1 |
Text |
Text
Text
|
|
|
|
|
|
|
|
|
|
|
Text |
|
Text |
|
Text |
|
Text |
|
Text |
|
Text |
Page |
|
Page |
|
Page |
|
Page |
|
Page |
|
Page |
|
|
|
|
|
|
|
|
|
|
|

. 9.17. 





SQL Server 7.0


















Microsoft 




















.
SQL Server 7.0 
















:
192 |
9. |
|
|
|
, |
- |
|
, |
. |
|
|
. |
. |
- |
|
. |
6.5, |
|
|
|
|
. |
|
- |
|
- |
|















, 

















.




. 















8 




. 






,














. 











, 



1, 


















.


(


extents). 




















8 













. 














. |
|
64 |
. |
126 |
. |








6.5 



















. 
-


































-

. 














:




(Uniform). 

























.
(Mixed). |
. |
|
, |
, |
. SQL 7.0 |
7 |
: |






(Data page),








(Index page)












(Log page),








(Text/image page),












(Global allocation map page),













(Page free space-page), 











(Index allocation map page).

















96 

. 
















, 




















. 


























. 


















:












<




, 





>,



, 












,






, 












,














, 












,















,



, 
























.



































-

: 



, 














, 




, 






















, 













- 



(
. 9.12).



- 



)
- 



)
-
. 9.12. 

































, 

















.


, 













.



.
























, 







-














.













.