[Info-vax] Indexed RMS file question

[J Xenu]

It's been a LONG time since I used indexed RMS files on VMS.

I have some data that I wish to place in an RMS indexed file, that is to be
accessed randomly using keys. The way I see it, there will be 3 or 4 keys.
Two will be text, of fixed length, with duplicates allowed. The other one or
two are integer, more on these later.

The lookups will be one of three methods:

1) Read a record that matches the first text key. Simple enough.

2) Read a record that matches both text keys. I want to read a record matching
   both the first and second keys. There may be more than one matching record,
   if so, I want to access them in order.

3) Using the first text key and an integer key, I want to read any record that
   matches the first key and the integer falls within the range of the third
   key.

Best described with an example: Assume the file has the content as follows:
(I'll leave out the second key since it's not relevant now)

Key 1  Key 3  Data

Alpha  1-18   data
Alpha  19-72  more data
Beta   1-10   bla bla
Beta   11     more stuff
Beta   12-32  even more data
Beta   33-50  This is the data I want
Beta   68-100 xxx
Gamma  1      yyy
Gamma  2-140  zzz

Assume I do a read with Key 1 = "Beta" and Key 3 = 42. I want the read to
return the record with data = "This is the data I want" since key 1 matches
and Key 3 falls within the range 33-50. How do I define the keys, especially
Key 3 without creating a duplicate record for each possible key3 value?
The ranges are pseudo-random, not multiples of anything. There can be gaps as
well, (for example "Beta", 62 in the example)