describe

Shows the characteristics of a table. desc is a short form.

Syntax

describe TABLE_NAME;
describe TABLE_NAME show columns [where name like 'MASK' [and chunkid = N]] [startid N] [limit N];

Result

Main
----
Name      : gaia_source
Owner     : system
Datacenter: DC1
Replicates: 1
Deployed  : yes
Wide      : no
Locked    : no
Partitions: 600
Sql       : empty
Col count : 152

• Wide says no, or yes - N chunks for a wide table.
• Partitions is the number of partitions; Locked tells whether the table is locked.
• Sql is the statement that created the table, or empty.

Listing the columns

A table with thousands of columns is never listed by default. Ask for what you want:

describe single_cell show columns where name like 'abi%' limit 3;
describe single_cell show columns where chunkid = 2;
describe gaia_source show columns startid 100 limit 5;

Each column is shown with its type and its position in the hash key (-1 if it is not part of it).

Wide tables

chunkid = N restricts the list to the columns of one chunk. limit and startid page through a very long list.

Privilege

None is needed to describe a table that exists.