Core statement calculations

The amount of shared memory which D3 may allocate for itself (which will be some fraction of the total amount of physical memory) may be changed by modifying the core statement value in the D3 configuration file. The maximum size is 200 GB . The maximum size for 64bit D3 is limited to the amount of physical RAM on the system, minus a reasonable amount for Linux. This calculation determines the amount of required shared memory for D3:

core = D3 ABS size + (Total D3 processes * nnKB) + D3 application memory

Parameter	Description
D3 ABS size	Size of the D3 ABS. D3 will run faster if the ABS (the D3 database system code) is loaded in memory at all times. See the D3 configuration file abslock statement if the ABS is not to be loaded in memory. Also, consider if the system is running standard D3 ABS or a custom ABS. Custom ABS may be considerably larger. Determine the size of any custom ABS. The D3 ABS uses approximately 4096 KB.
Total D3 processes	D3 processes that are being executed. D3 processes include: Maximum number of concurrently running D3 (terminal and modem) users Total number of printers on the D3 system Maximum number of concurrently running D3 phantom processes Maximum number of concurrently running D3 processes executing UNIX shell processes It should `not` include the total number of users and processes, but rather the maximum number of users that are consistently logged on at one time and the maximum number of processes that are consistently executing at the same time. For the multiplying factor `nn`: For non-FlashBASIC applications, use a factor of 350 KB. For FlashBASIC applications, use a factor of only 50 KB. (FlashBASIC applications transfer memory requirements to the UNIX side of shared memory and to UNIX swap space.)
D3 application memory	Amount of memory required by the application to perform its operation, that is, the amount of memory required to obtain suitable performance during file searching and sorting operations. This value may be estimated according to the size of the database as follows:
	Database Size	Memory Requirements
	< 100 MB	2500 KB
	100 - 200 MB	3000 KB
	200 - 300 MB	4000 KB
	300 - 400 MB	5000 KB
	400 - 500 MB	6000 KB
	500 - 600 MB	6500 KB
	600 - 750 MB	7500 KB
	> 750 MB	1 % of the database size