How to remove random rows from kdb table?

Question

How to delete the first 10 rows from kdb table? I want to remove only the first 10 rows returned from:

select [10] from mytable

I tried using delete with index i, but the number of rows is not decreasing:

 count mytable 2201784 delete from mytable where i < 10 count mytable 2201784

Also, the delete operator returns a few lines of my Q console, not sure what it is.

+4

Robert Kubrick Jun 04 '13 at 11:56

3 answers

you can use the drop _ operator in the table and have 10 as an argument LHS mytable: 10 _mytable

+3

Jpc Jun 04 '13 at 14:31

 delete from mytable where i<10

0

mnestor Jun 04 '13 at 12:13

skeevey · Accepted Answer · 2013-06-04T12:54:59+0000

If you want to remove a place from a table, you must reference it by name.

 delete from `mytable where i < 10

Alternatively reassign:

 mytable:delete from mytable where i<10

When you start delete from mytable where i<10 it returns the table with the changes made, but does not apply them to mytable stored in memory.

Http://code.kx.com resources answer many questions regarding the daily use of kdb.