TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

Appendix H 683
TurboIMAGE/XL versus TurboIMAGE/V
Moving from MPE/iX to MPE V
particular number of users, the default number of buffers is used. These are the default
settings assigned by TurboIMAGE on MPE V:
b(1/2) b+4( 9/10) b+7(15/16)
b+1(3/4) b+5(11/12) b+8(17/18)
b+2(5/6) b+6(13/14) b+9(19/120)
b+3(7/8)
The value of b is equal to the largest number of search items in any detail data set in the
database plus 3, or it is equal to 8, whichever is larger.
If p is the maximum number of search items (the path count), the value of b can be
represented as follows:
b = max (p+3,8)
For example, the largest path count for a detail data set in the ORDERS database is 4.
(This is the path count for the CUST data set.) Therefore, the value of b for the ORDERS
database is shown here:
b = max (4+3,8) = 8
The default buffer specifications in this case are:
8(1/2),9(3/4),10(5/6),11(7/8),12(9/10),13(11/12),14(13/14),15(15/16),16(17/18),17(19/120)
Example 1
:RUN DBUTIL.PUB.SYS Initiate DBUTIL execution.
.
.
.
>>SET ORDERS BUFFSPECS=5(1/120) Specify 5 buffers to be allocated for from 1
For database ORDERS to 120 users (access paths).
BUFFER SPECIFICATIONS: DBUTIL confirms the specifications
by listing them.
5(1/120)
>>
Example 2
:RUN DBUTIL.PUB.SYS
.
.
.
>>SHOW ORDERS BUFFSPECS Check the current buffer
specifications.
BUFFER SPECIFICATIONS:
5(1/120)
>>SET ORDERS BUFFSPECS=30(1/30) Specify the new buffer