gpadmin=# \d pg_catalog.gp_configuration

Table "pg_catalog.gp_configuration"

Column | Type | Modifiers
----------------+----------+-----------
content | smallint | not null
definedprimary | boolean | not null
dbid | smallint | not null
isprimary | boolean | not null
valid | boolean | not null
hostname | name | not null
port | integer | not null
datadir | text | 
Indexes:
"gp_configuration_content_definedprimary_index" UNIQUE, btree (content, definedprimary), tablespace "pg_global"
"gp_configuration_dbid_index" UNIQUE, btree (dbid), tablespace "pg_global"
Tablespace: "pg_global"