First look for index name for the PK (pk_idx column)
select c.constrname, c.constrtype as tp , c.idxname as pk_idx , t2.tabname, c2.idxname
from sysconstraints c, systables t, outer (sysreferences r, systables t2, sysconstraints c2)
where t.tabname = "asamembr"
and t.tabid = c.tabid
and r.constrid = c.constrid
and t2.tabid = r.ptabid
and c2.constrid = r.constrid
where the constrtype :
constrtype CHAR(1) Code identifying the constraint type:
C = Check constraint
N = Not NULL
P = Primary key
R = Referential
T = Table
U = Unique
Then , check the index columns (look for the same index name of the PK constraint):
select unique
t.tabname
, i.idxname
, i.idxtype
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part1 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part2 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part3 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part4 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part5 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part6 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part7 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part8 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part9 )
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part10)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part11)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part12)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part13)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part14)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part15)
, (select c.colname from syscolumns c where c.tabid = i.tabid and c.colno = i.part16)
from sysindexes i , systables t
where i.tabid = t.tabid
and t.tabname = "asamembr";
where idxtype:
idxtype CHAR(1) Index type:
U = Unique
D = Duplicates allowed
G = Nonbitmap generali
g = Bitmap generalized
u = unique, bitmap
d = nonunique, bitmap
Search at Informix online manuals for "sysconstraints" or "sysindexes"