Searching
DRAFT
Fast searching is a key aspect of kdb+. Searching a vector is efficient and straightforward. Searching other data structures requires more care.
Vector
q)f1k:1000{x,sum -2#x}/0 1 / first 1000 Fibonacci numbers
q)(f1k>1000000000)?1b / ordinal of first > 1 billion
45
x is a vector and y of the same type, Find is right-atomic
q)type each "bad beef"?/:("a";"bc") / returns atom and list
-7 7h
q)"bad beef"?2 4#"abcdefgh"
1 0 8 2
5 7 8 8
q)"bad beef"?("bee";("bread";"bead");"abed")
0 5 5
(0 8 5 1 2;0 5 1 2)
1 0 5 2
To do
- Type sensitivity
- Rank sensitivity
- Index At
- Tables
likessexceptinwithin