I am assuming this is an opaque data type.

Is it possible to select from the various fields in indexkey.

Where are these methods documented.

My background predates these structures.

From the SQL Reference Guide:


INDEXKEYARRAY
This column has a maximum of three fields,
displayed in the following form:

<function id>(col1, ... , coln) [operator class id]


The fields within the indexkeys columns have the following significance:

The function id appears only if the index is on return values of a
function that is defined over the columns of the table. (That is, if the
index is a functional index.) Here the function id is the same as the
procid value for the function in the sysprocedures table.

The list of the columns (col1, ... , coln) in the second field identifies the
columns over which the index is defined.

The operator class id shows the secondary access method that is used
to build and to search the index. Here the operator class id is the same
as the opclassid of the access method in the sysopclasses table.

Thanks - but I have already read the Guide.

What I couldn't see is how I can access the fields within indexkeys
directly.

I have since used sysindexes to do what I wanted to do (generate SQL for UPDATE STATISTICS).

Sysindexes is a view in Informix 9.3 (a table in 7.*).

Looking at this view we find the following method
ikeyextractcolno(x0.indexkeys ,0 )

This does not appear to be documented - and I guess sysindexes is (or will be) deprecated.

I wanted to know more.

Ok - sorry about that

Did you look into the http://iiug.org for any scripts?