|
Jun
29 |
|
answered | fills on zeros in KDB |
|
Apr
20 |
|
awarded | Yearling |
|
Apr
20 |
|
awarded | Yearling |
| 2023 | |||
|---|---|---|---|
|
Apr
30 |
|
comment |
KDB:Can kdb solve the topn problem without sorting Let's say you want to find n largest elements of an array of size N. On average you'd need O(N log N) operations to sort the array first with "sort first and take top n" approach or, alternatively, you can maintain a min-priority queue of size n, traverse the array and insert an element if it is greater than the least element of the queue O(log n) and thus reduce the complexity down to O(N log n). If you did this in pure q, however, you wouldn't get any performance benefit because you'd have to write loops almost certainly. So it's either sort-first or a C extension if you absolutely need it |
|
Apr
20 |
|
awarded | Yearling |
|
Apr
20 |
|
awarded | Yearling |
|
Apr
15 |
|
awarded | Critic |
|
Apr
5 |
|
comment |
Find even numbers upto n in kdb? It believe your example is written in k9 which is not supported by kdb by kx. ~x!2 can be written in q like this: not x mod 2 so it does use mod. Why do you want to avoid it?
|
|
Mar
13 |
|
answered | What is the difference between 'and' or '&' in kdb? |
| 2022 | |||
|
Nov
10 |
|
awarded | kdb |
|
Nov
8 |
|
answered | kdb: can I use the set keyword to achieve @[`.;`upd;:;.some.function]? |
|
Oct
31 |
|
revised |
Can temporals be used as columns in KDB? deleted 3 characters in body |
|
Oct
31 |
|
revised |
Can temporals be used as columns in KDB? added 370 characters in body |
|
Oct
31 |
|
answered | Can temporals be used as columns in KDB? |
|
Oct
18 |
|
answered | How do I aggregate on all columns in KDB? |
|
Apr
21 |
|
awarded | Yearling |
|
Apr
20 |
|
awarded | Yearling |
|
Apr
9 |
|
answered | How do I evaluate a function into a matrix in KDB? |
|
Jan
14 |
|
awarded | Supporter |
| 2021 | |||
|
Sep
3 |
|
revised |
Optimize KDB query time to get rolling average price from each contributor added 217 characters in body |