[megan_mcp]

Hi @biman

I am sorry to hear you are experiencing issues with our academy.

Can you try accessing the academy in incognito mode ?

If you are trying to access the KX Sandbox through the academy, you can do this by going directly to “edu.kx.com”.

If this issue still persists, please let me know and we will investigate it further.

Thanks,

Megan

[megan_mcp]

Hi @newstudent2017

This operation is used internally by kdb+ to represent the flip of a memory-mapped splayed table. When loading a database with \l, the tables in the database are added to the root namespace using this operation.

x!y ![x;y]

The result must be flipped in order to use it as a table. After doing that, select statements will operate on the on-disk table. Many operations (including certain overloads of select) will throw a par error when used on this table.

Examples:

q):db/t/ set ([]a:1 2)<br>:db/t/
q)\l db
q).Q.s1 t
"+(,a)!:./t/"

It is possible to manually create this representation:

q)enlist[a]!:./t/
(,a)!:./t/
q)flip enlist[a]!:./t/
a
-
1
2

The equivalent for a partitioned table:

q):db/2001.01.01/t/ set ([]a:1 2)<br>:db/2001.01.01/t/
q):db/2001.01.02/t/ set ([]a:3 4)<br>:db/2001.01.02/t/
q)\l db
q).Q.s1 t
"+(,a)!t"
q)enlist[a]!t
(,a)!t
q)flip enlist[a]!t
date       a
------------
2001.01.01 1
2001.01.01 2
2001.01.02 3
2001.01.02 4

If the specified table does not exist on disk, the expression remains unresolved and any attempt to select from it fails:

q)flip enlist[a]!:./s/
+(,a)!:./s/
q)select from flip enlist[a]!:./s/
'./s/a. OS reports: No such file or directory
  [0]  select from flip enlist[a]!:./s/
q)flip enlist[a]!s
+(,a)!s
q)select from flip enlist[a]!s
's
  [0]  select from flip enlist[a]!s
       ^

We are adjusting our documentation to make this clearer in future.

If you have any further questions, please let me know!

Thanks,

Megan

[megan_mcp]

Hi @baichen111

Thank you for reporting this. We will investigate this further and adjust it accordingly.

Thanks,

Megan

[megan_mcp]

Hi @miaaaal

Apologies for the late response.

You have defined your .z.pw function correctly, but you now must apply this to .perm.users to give them access.

Thanks,

Megan

[megan_mcp]

Hi @user931206

Is it possible you could send a screenshot of the code rather than pasting it in the editor?

Apologies as this is a problem on our end, not yours.

Thanks,

Megan

[megan_mcp]

Hi @newstudent2017

In the documentation it states “the derived function ‘[f;ff] has the rank of ff and returns f ff[x;y;z]“

If we use the following examples:

q)ff:{[w;x;y;z]w+x+y+z}

q)ff[1;2;3;4]

10

If the syntax returns f ff[x;y;z] then essentially the result for ff[w;x;y;z] is our x parameter for f.

We know that ff[1;2;3;4] = 10

q)f:{2*x}

q)f[10]

20

We use composition to combine these steps together:

q)'[f;ff][1;2;3;4]

20

If you have any questions about this, please let me know!

Thanks,

Megan

[megan_mcp]

Hi @moshe-hamaoui

Your error message seems to be correct.

Can you send me your full .f1.checkSensor function in normal text (without the code tag)?

Thanks,

Megan

[megan_mcp]

Hi @roryk

If the content of the file contains spaces, 0: only loads a subset of the data.

It could also just be the read vs mmap performance.

Hope this helps.

Thanks,

Megan

[megan_mcp]

Hi @Treese_H85

Apologies for the delay in response.

Can you make sure you are not running this cell after defining .z.pg, as this reverts it on the server process.

Let me know if this works !

Thanks,

Megan

[megan_mcp]

Hi @KDDevLearning

Just so that I understand correctly, you missing the following button in your lessons?

Thanks,

Megan

[megan_mcp]

Hi @nihS

When the question states “Define a function on our local process” – this is the process you saved to hdbH.

Try defining the function on this process instead.

Thanks,

Megan

[megan_mcp]

Hi @Sosycs

As an example I’ve used snippets from our Document Search sample (screenshot below):

Simply change the metric to: “metric” : “CS”.

To see the distance print the results of the similarity search (the distance will be in a column in the result called “__nn_distance”:

print(table.search(query_vector, n=3))

Also take a look at our documentation on cosine similarity for extra help – KDB.AI Similarity Metrics – Documentation (kx.com)

Hope this helps!

Thanks,

Megan

code.kx.com

KDB.AI Similarity Metrics - Documentation

Supported metrics in KDB.AI

[megan_mcp]

Hi @moshe-hamaoui

I have sourced the issue and apologies that it is so minor.

When I tested your code, I was receiving the error you had mentioned above however when I replaced the message with one that is provided in the project file, the test case passed.

I believe it was the format of the hyphen that caused this issue.

As you can see in screenshot_1 (provided below) the hyphen used in your code is slightly thinner than the hyphen used in the message provided (screenshot_2).

The test case must have picked up as a different character, hence why the test case failed.

If you have any further questions please let me know.

Thanks,

Megan

[megan_mcp]

@roryk

I can follow up on this further if you would like to know why read0 doesn’t use memchr (&/ mmap)?

[megan_mcp]

Hi @roryk

I reached out to one of our developers on this and this was their response:

“Actually looks like read0 is using a load of memcmp calls & scanning for \n
where 0: is using memchr to find it in a single call:

q)\ts:1 (1#"*";"-")0:`:testf 
221 36800   
seconds  usecs/call     calls      function 
-------- ----------- --------- -------------------- 
0.095358          95      1003 memchr 
0.060194         106       564 memmove  
240799   0.000319 memchr("qwertyuiopasdfghjklzxcvbnm\nqwert"..., '\n', 13311)                              
= 0x7fa1eaf3d0d7 
240799   0.005258 memchr("qwertyuiopasdfghjklzxcvbnm\nqwert"..., '-', 26)                                  
= 0 
240799   0.005147 memmove(0x7fa1e6b121d0, "qwertyuiopasdfghjklzxcvbnm", 26)                                
= 0x7fa1e6b121d0

q) \ts:1 read0 `:testf
2161 52624

seconds usecs/call calls function
-------- ----------- --------- --------------------
1.332051 98 13505 memcmp

0.102397 97 1046 memmove

240799 0.000144 memcmp(0x4bf876, 0x7fa1e6b7f410, 1, 113) = 0xffffff93

240799 0.000152 memcmp(0x4bf876, 0x7fa1e6b7f411, 1, 119) = 0xffffffa5

240799 0.000172 memcmp(0x4bf876, 0x7fa1e6b7f412, 1, 101) = 0xffffff98

240799 0.000160 memcmp(0x4bf876, 0x7fa1e6b7f413, 1, 114) = 0xffffff96

240799 0.000144 memcmp(0x4bf876, 0x7fa1e6b7f414, 1, 116) = 0xffffff91

240799 0.000144 memcmp(0x4bf876, 0x7fa1e6b7f415, 1, 121) = 0xffffff95

240799 0.000144 memcmp(0x4bf876, 0x7fa1e6b7f416, 1, 117) = 0xffffffa1

240799 0.000154 memcmp(0x4bf876, 0x7fa1e6b7f417, 1, 105) = 0xffffff9b

240799 0.000162 memcmp(0x4bf876, 0x7fa1e6b7f418, 1, 111) = 0xffffff9a

240799 0.000236 memcmp(0x4bf876, 0x7fa1e6b7f419, 1, 112) = 0xffffffa9

240799 0.000150 memcmp(0x4bf876, 0x7fa1e6b7f41a, 1, 97) = 0xffffff97

240799 0.000149 memcmp(0x4bf876, 0x7fa1e6b7f41b, 1, 115) = 0xffffffa6

240799 0.000149 memcmp(0x4bf876, 0x7fa1e6b7f41c, 1, 100) = 0xffffffa4

240799 0.000222 memcmp(0x4bf876, 0x7fa1e6b7f41d, 1, 102) = 0xffffffa3

240799 0.000175 memcmp(0x4bf876, 0x7fa1e6b7f41e, 1, 103) = 0xffffffa2

240799 0.000313 memcmp(0x4bf876, 0x7fa1e6b7f41f, 1, 104) = 0xffffffa0

240799 0.000311 memcmp(0x4bf876, 0x7fa1e6b7f420, 1, 106) = 0xffffff9f

240799 0.000312 memcmp(0x4bf876, 0x7fa1e6b7f421, 1, 107) = 0xffffff9e

240799 0.000239 memcmp(0x4bf876, 0x7fa1e6b7f422, 1, 108) = 0xffffff90

240799 0.000149 memcmp(0x4bf876, 0x7fa1e6b7f423, 1, 122) = 0xffffff92

240799 0.000148 memcmp(0x4bf876, 0x7fa1e6b7f424, 1, 120) = 0xffffffa7

240799 0.000218 memcmp(0x4bf876, 0x7fa1e6b7f425, 1, 99) = 0xffffff94

240799 0.000156 memcmp(0x4bf876, 0x7fa1e6b7f426, 1, 118) = 0xffffffa8

240799 0.000148 memcmp(0x4bf876, 0x7fa1e6b7f427, 1, 98) = 0xffffff9c

240799 0.000208 memcmp(0x4bf876, 0x7fa1e6b7f428, 1, 110) = 0xffffff9d

240799 0.000326 memcmp(0x4bf876, 0x7fa1e6b7f429, 1, 109) = 0

240799 0.000270 memmove(0x7fa1e6b121d0, "qwertyuiopasdfghjklzxcvbnm", 26) = 0x7fa1e6b121d0

240799 0.000174 memmove(0x7fa1e6b75f78, "\300!\261\346\241\177\0\0", 8) = 0x7fa1e6b75f78