Interstage Shunsaku Data Manager Application Development Guide - Microsoft(R) Windows(R) 2000/ Microsoft(R) Windows Server(TM) 2003 - - UNIX -

C.3 Allowable Values for Aggregation Requests

The following table lists the allowable values associated with aggregation requests.

[Table C-6 Allowable Values for Aggregation Requests]

Item	Allowable value	Remarks
Maximum number of keys that can be specified	8	-
Sort expression	From 1 to 65, 535 bytes (excluding \0)	-
Total length of group keys	1 to 2,000 bytes	The total group key length is the total length of all the group keys in key specifications. Refer to Relationship between the Total Group Key Length and the Total Number of Items that Can be Returned for more information on how the total group key length affects the number of items that can be returned.
Number of characters returned when the rlen function is used in key specifications	1 to 128	The length of the character string resulting from the rlen function is shown in the table entitled "Relationship between character code and the length of the string resulting from the rlen function".
Number of items that can be returned	100 to 1,000 records	When the total length of group keys is 200 bytes or less, the records corresponding to the top 1,000 groups can be returned. If the total length of group keys exceeds 200 bytes, the number of groups that can be returned is indicated in Relationship between the Total Group Key Length and the Total Number of Items that Can be Returned.

Relationship between the Total Group Key Length and the Total Number of Items that Can be Returned

The total group key length is the total length of all the group keys in key specifications. The length of each key is determined by the key specification format, as shown in the following table.

[Table C-7 Relationship between Total Group Key Length and the Number of Returnable Items]

Key specification format	Length of group key	Remarks
val function	16 bytes	-
Text format	20 bytes	The first 20 bytes are grouped as the key. To group using a string that is longer than 20 bytes, specify the rlen function as the key specification of the sort expression. By specifying the rlen function, it becomes possible to perform grouping using up to 128 characters as a key.
rlen function	The length of the character string resulting from the rlen function is shown in the table entitled 'Relationship between character code and the length of the string resulting from the rlen function'.	-

The character code of the director data determines the byte length of each character of the character string produced by the rlen function, as shown below.

[Table C-8 Relationship between Character Code and the Length of the String Resulting from the rlen Function]

Character code	No. of bytes per character	Example
UTF-8	4 bytes	rlen(/root/name/text(),50) would be treated as 200 bytes.
GB18030
SHIFT-JIS	2 bytes	rlen(/root/name/text(),50) would be treated as 100 bytes.
GB2312
big5
KSC5601
EUC	3 bytes	rlen(/root/name/text(),50) would be treated as 150 bytes.

The following table shows how the total group key length affects the number of groups that Shunsaku can return.

[Table C-9 Group Key length and the Number of Groups that can be Returned by Shunsaku]

Group key length (bytes)	Number of groups that can be returned
1 to 200	1,000
201 to 300	700
301 to 400	500
401 to 500	400
501 to 700	300
701 to 1,000	200
1,001 to 2,000	100