Question

I’m looking for a better way of searching through numeric ranges in Oracle Text. I have a DB app that does a lot of GIS-type things, but we now want to add street range searching to it.

So I’d like to store the min and max values in a column, and search for a number within those values. I’m happy to go explore options, but I’d like some pointers on where to head. Does anyone have any suggestions for me?

EDIT: we’re just trying to make address lookups easier. Text on the address parts has been a huge success, but we want to store street ranges instead of every individual house number.
So, if I searched for “11 high street”, I’d expect a match if high street had a range of 1 to 1000. I’d also like some options that I can use if I searched for “flat 1 11 high street” too though. I expect that I will have to do some jiggery with the input in these cases, I just want to know what kind of tools there are that I could try working with.

Answer 1

My suggestion is to make standard length string field for storing building numbers, create index on this field and then use between for search.

Something like this format:

NNNNNNCCCCBBBB

where:

NNNNNN – left-padded house number;
CCCC – left-padded character (like ‘A’ in ’11A’);
BBBB – left-padded building number

Under ‘left-padded’ I mean “filled with some symbol to standard length at left side”, see for example result of select lpad('11',5,'X') from dual; query.

E.g. suppose, you have “11A high street building 5” address and choose ‘%’ as filling symbol. When converted to proposed format it looks like '%%%11%%%A%%%' and ‘high street’ stored at separated field(s).
Next is query example for selecting all houses between 1 and 1000:

with address_list as (
  select '%%%11%%%A%%%%' bnum from dual union all
  select '%1001%%%A%%%%' bnum from dual union all
  select '%%%%1%%%A%%%%' bnum from dual union all
  select '%%%%1%%%%%%%%' bnum from dual union all
  select '%%321%%%A%%%%' bnum from dual union all
  select '%1000%%%A%%%%' bnum from dual union all
  select '%1000%%QQ%%12' bnum from dual 
)
select * from address_list
where 
  -- from '1 high street'
  bnum >= '%%%%1%%%%%%%%' 
  and                    
  -- less then '1001 high street'            
  bnum < '%1001%%%%%%%%' 
order by 
  bnum

In real case is better to use chr(1) or any other unprintable symbol as symbol for padding.

Another thing is to build only function-based index for search without real field storage.