DESCRIBE `テーブル名`

SHOW COLUMNS FROM `テーブル名` [FROM db_name] [LIKE wild]

sp_columns [テーブル名]

select

pg_attribute.attname
,replace(pg_type.typname,'_','') as typename
,pg_attribute.atttypmod-4 as charlen
,pg_attribute.atttypid
,pg_attribute.attnum

from 
pg_class
inner join pg_attribute
on pg_class.relfilenode = pg_attribute.attrelid
inner join pg_type
on pg_attribute.atttypid = pg_type.typelem

where pg_class.relname = 'テーブル名'
and pg_attribute.attnum > 0

order by pg_attribute.attnum

select *
from
USER_TAB_COLUMNS
where
TABLE_NAME = 'テーブル名'
order by COLUMN_ID