https://learninghub.kx.com/forums/topic/xasc-data-on-disk-compressed
From a question on topicbox:
Sorting data on disk as per code.kx.com, even when compressed
q).z.zd:17 2 6
q)tab:flip {`dt`tm`sym`ap`bp!(x?.z.d+til 10;x?08:00+01:00*til 8;x?4?`4;x?5.0;x?5.0)}10000
q)`:db/tab/ set .Q.en[`:db]tab `:db/tab/
q)meta get `:db/tab/
c | t f a
---| -----
dt | d
tm | u
sym| s
ap | f
bp | f
q)`tm xasc `:db/tab/ `:db/tab/
q)meta get `:db/tab/
c | t f a
---| -----
dt | d
tm | u s
sym| s
ap | f
bp | f
q)-21!`:db/tab/dt
compressedLength | 6611
uncompressedLength| 40016
algorithm | 2i
logicalBlockSize | 17i
zipLevel | 6i