informix maximum length primary key

[loginStd]

HI,

I would create the following table on Informix 9.4:

create table table_client_mappings (
principal integer not null,
sync_source varchar(128) not null,
luid varchar(200) not null,
guid varchar(200) not null,

primary key (principal,sync_source,luid,guid)
constraint pk_clientmapping
);

but the creation of the pk_clientMapping constraint fails because it exceeds the maximum key length.

How could I create the table with that PK?
Is there a max length for PK?

Thanks in advance
Luigia

 

[cdlvj]

From the manual

You can include up to 16 columns in a composite index. The total width of all
indexed columns in a single CREATE INDEX statement cannot exceed
255 bytes. ¨
XPS

 

[cdlvj]

Actually looks like 390 bytes is the limit.

A composite index can have up to 16 key parts. An index key part is either a
table column or the result of a user-defined function on one or more table
columns. A composite index can have any of the following items as an index
key:
n One or more columns
n One or more values that a user-defined function returns (referred to
as a functional index)
n A combination of columns and user-defined functions
The total width of all indexed columns in a single CREATE INDEX statement
cannot exceed 390 bytes. ¨