[rocuinneagain]

Everything looks correct in that screenshot. You just need to open your web browser and enter http://localhost:10001 in your address bar.

 

For starting KX Developer I wrote a simple developer.bat file which I can double click to start both the developer and have my web browser open to the correct URL. You could do similar for KX Dashboards.

My developer.bat contains:

 

call C:developerconfigconfig.bat 
start "developer" "q" 
C:developerlauncher.q_ 
start "" http:localhost:%developer_PORT%/ax

 

[rocuinneagain]

This conversation could help:

Using PyQ in PyCharm Issue #61 KxSystems/pyq (github.com)

[rocuinneagain]

To launch pyq you need to call the pyq executable instead of the python executable.

https://code.kx.com/q/interfaces/pyq/#quick-start

This:

$ pyq

 

Not this:

$ python

 

Related questions raised on stackoverflow.com

• kdb – How do i start KX Developer – Stack Overflow
• kdb – How do I install PYQ in Conda or Pycharm? – Stack Overflow
• kdb – KX Developer launcher error how can i fix it? – Stack Overflow

 

For Developer

https://code.kx.com/developer/getting-started/#starting-developer

You need to start it with

 

source /path-to-install-dir/config/config.profile q /path-to-install-dir/launcher.q_

 

For your SSH error this may help:  How to install libssh2-1 on Ubuntu 20.04 (Focal Fossa)? (devmanuals.net)

 

 

[rocuinneagain]

You need to run both commands in the same ssh terminal. It does not work when you do it in 2 different ones like you screenshot.

[rocuinneagain]

The q language is documented with lots of learning materials on: https://code.kx.com/q/

There are also courses on https://kx.com/academy/

 

k is the underlying language which you do not need to interact with. See this note: https://community.kx.com/t5/New-kdb-q-users-question-forum/rotate-function-differences-between-k-and-q/m-p/13186/highlight/true#M544

[rocuinneagain]

You can trap using . or @

https://code.kx.com/q/ref/apply/#trap

 

 

[rocuinneagain]

 

q)h:hopen `::5678 
q)h({set;`myVariable;1 2 3 4 5) 
/or 
q)h({x::y};`myVariable;1 2 3 4 5)

• https://code.kx.com/q/ref/get/#set
• https://code.kx.com/q/ref/overloads/#colon-colon
• https://code.kx.com/q/wp/ipc/#synchronous-queries

[rocuinneagain]

Only symbols. You can view their memory usage in .Q.w[]

• syms: number of interned symbols
• symw: bytes used by interned symbols

https://code.kx.com/q/ref/dotq/#qw-memory-stats

[rocuinneagain]

lsof and netstat can give you information about the open handles even if you cannot connect yourself

[rocuinneagain]

There are some notes on late data in this blog post: https://kx.com/blog/partitioning-data-in-kdb/

It outlines the basics of using lookup tables per partition.

 

Another option involves taking copies of HDB partitions and upserting the late data to the copy.

Then this new partition with extra data replaces the old one. Coordination is needed to ensure any HDB process reading the data does not error during this process.

[rocuinneagain]

https://code.kx.com/q/basics/errors/#:~:text=conn,connections%20(1022%20max)

The conn error happens when the limit of 1022 open connections is hit.

Some process(es)  must be continuously opening handles but not closing them after use.

You can count .z.W  at any time to see how many open handles there are.

-38! can give you information on the type of each open handle.

At any time you can force close handles using hclose.

 

To trace the source of the problem you can add logging and monitoring to the port open and close call-backs,  .z.po and .z.pc.

One example is the dotz library which you can customise to your needs.

 

 

[rocuinneagain]

Regular Expressions can be used to define axes instead of a data source column:

https://code.kx.com/dashboards/canvascharts/#regex-for-data

 

[rocuinneagain]

I tested this in 3.6 2019.04.02 could reproduce it.

The issue is not present in 3.6 2020.05.04.

Release notes of fix:

2019.05.24 FIX reading enums in log format could leak memory. e.g.

q)h:hopen`:a set ();
h enlist(`u;`sym?`a`b`c);
hclose h;
do[5;get`:a;0N!.Q.w[]`used]

 

[rocuinneagain]

You cannot do inline temporary variable creation as @eohara pointed out.

 

Instead you can use a lambda to avoid performing the calculation twice:

q)select {[a;b] (total+5)%(total:a+b)}[a;b] from t 
b 
-------- 
2 
1.714286 
1.555556

 

[rocuinneagain]

You can run:

q)system”taskset -pc “,string .z.i

“pid 73’s current affinity list: 0-7”