Two comma-separated values configure the $ZF heap. From left to right:
zfstrsz is the number of characters Caché allows for a single string parameter on the $ZF heap. How many bytes this actually requires depends on whether you are using 8-bit characters, Unicode (2-byte characters), or 4-byte characters on UNIX®. The range is 032767. A value of 0 tells Caché to determine an appropriate value for zfstrsz automatically. The default is 32767 characters.
zfheapsz is the number of bytes Caché allocates for the $ZF heap for all purposes. The $ZF heap consists of the total number of bytes allocated in virtual memory for all $ZF input and output parameters, including the space for strings allowed by the first value. The range is 0270336 bytes. The default is 0. A value of 0 tells Caché to calculate an appropriate value for zfheapsz automatically, based on the value of zfstrsz.