Simple Oracle query hangs depending on WHERE clause
following the advice of a_horse_with_no_name,


  Please show us the execution plan for the second query –
  a_horse_with_no_name 4 hours ago


I have posted the relevenat parts of the execution plan... however I can't make heads or tails of what is wrong with it from that....  

I followed Mat's advice and guess that lack of indexing is the issue.  Because there is no indexing, it must be as Matt says, that this simple query is doing a full table scan, which could take longer than the few minutes I have been waiting for the query to complete...

Useful link about the concept of indexing: http://www.orafaq.com/node/1403


  Is that column indexed? Otherwise you'll get a full table scan, which
  can take a while if the table is big. – Mat 7 hours ago
  
  select index_name, column_name from dba_ind_columns where index_owner
  = 'THE_SCHEMA' and table_name = 'YOUR_TAB' order by index_name will get you all the indexed columns. Look at the explain plan to see what
  it is doing (look into set autotrace or use a GUI that has that
  feature, like sqldeveloper) – Mat 7 hours ago


Thanks for your help guys.  Let me know if I might be wrong in that assumption, or if you might have additional insight a_horse_with_no_name....