Mar 7, 2011

What are some of the hard limits of kdb I should know about?

no more than 2GB over IPC
number of tables mapped is limited by number of file descriptors allowed by OS
maximum of 32 global references per function
maximum of 23 local variables per function
maximum of 96 constants within a function
enums are limited to 57 – (type values 20h to 76h)
4096 maximum compressed files open (for versions earlier than 3.1T2013.02.21)
999 nested columns in splayed table
1022 maximum incoming network connections
maximum of eight function parameters
maximum number of mapped nested columns 1024
maximum number of active `g# indices 1024
maximum branch (if; do; while; $[]) distance is 255 byte codes away (from PC to PC+255bytes!) – if you get a ‘branch error, you have to break the code up into smaller pieces