CODEWITHSUNDEEP
kdb+
S.V
S.V

Reputation: 2793

What is the meaning of KDB table of type 0h?

This is what I am observing:

q)type select date,time from table
98h
q)type select date,time,size from table
0h
q)select date,time,size from table
date       time                          size  
------------------------------------------------
2007.01.03 2007.01.03D09:31:00.000000000 200    
2007.01.03 2007.01.03D09:31:00.000000000 313869 
2007.01.03 2007.01.03D09:31:00.000000000 114852 
2007.01.03 2007.01.03D09:31:00.000000000 566600 
..

Why does the resulting table have type 0h? What is the meaning of it? Why adding size to the query changes the result type? Thank you.

Upvotes: 1

Views: 3126

Answers (1)

Sean O'Hagan
Sean O'Hagan

Reputation: 1697

It means a mixed list - https://code.kx.com/q/basics/datatypes/

Thus - size is a mixed type. You can group the column into its types and identify the offending indices by running:

exec i group type each size from table

To get the column into a typed column you will need to run a cast to convert them to your required type. Perhaps your time column has a mix of ints and longs for example, just cast them to what you require.

Upvotes: 2

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