Dealing with alternate spelling in English

Question

Hi Gurus,
How can we retrieve words like Colur and Labour when we use color and labor as search terms other than using stem operator.
Thanks,
Vikas

Answer 1

Please find code below.
-- creating a table
create table test_sh4 (text1 clob,text2 clob,text3 clob);
-- inserting some data into table
INSERT INTO TEST_SH4 VALUES ('colour','colour  labour','y');
INSERT INTO TEST_SH4 VALUES ('color','color  labor','y');
commit;
-- creating preferences
begin
   ctx_ddl.create_preference ('test_mcd', 'multi_column_datastore'); -- utilizing the same index for multiple columns
    ctx_ddl.set_attribute
      ('test_mcd',
       'columns',
       'regexp_replace(text1,''[[:punct:]*|[[:space:]*]'') nd1, -- virtual column to eliminate white spaces and punctuation marks  in text1 column
        text1 text1, 
        regexp_replace(text2,''[[:punct:]*|[[:space:]*]'') nd2,  -- virtual column to eliminate white spaces and punctuation marks   in text2 column
        text2 text2');
    ctx_ddl.create_preference ('test_lex1', 'basic_lexer');
    ctx_ddl.set_attribute ('test_lex1', 'whitespace', '/\|-_+&'); --translating special characters as white space using lexer
    ctx_ddl.create_section_group ('test_sg', 'basic_section_group'); -- creating section group to search within sections.
    ctx_ddl.add_field_section ('test_sg', 'text1', 'text1', true);
    ctx_ddl.add_field_section ('test_sg', 'nd1', 'nd1', true);
    ctx_ddl.add_field_section ('test_sg', 'text2', 'text2', true);
    ctx_ddl.add_field_section ('test_sg', 'nd2', 'nd2', true);
     ctx_ddl.create_preference('SUBSTRING_PREF', 'BASIC_WORDLIST');
    ctx_ddl.set_attribute('SUBSTRING_PREF','SUBSTRING_INDEX','TRUE');
     ctx_ddl.set_attribute('SUBSTRING_PREF','PREFIX_INDEX','TRUE');
     ctx_ddl.set_attribute('SUBSTRING_PREF','PREFIX_MIN_LENGTH', '3');
     ctx_ddl.set_attribute('SUBSTRING_PREF','PREFIX_MAX_LENGTH', '8');
     ctx_ddl.create_preference('textstore', 'BASIC_STORAGE');
    ctx_ddl.set_attribute('textstore', 'I_TABLE_CLAUSE','tablespace CAPT_DATA storage (initial 64K next 64K)');
    ctx_ddl.set_attribute('textstore', 'K_TABLE_CLAUSE','tablespace CAPT_DATA storage (initial 64K next 64K)');
     ctx_ddl.set_attribute('textstore', 'R_TABLE_CLAUSE','tablespace CAPT_DATA storage (initial 64K) lob (data) store as (cache)');
    ctx_ddl.set_attribute('textstore', 'N_TABLE_CLAUSE','tablespace CAPT_DATA storage (initial 64K)');
    ctx_ddl.set_attribute('textstore', 'I_INDEX_CLAUSE','tablespace CAPT_INDEX storage (initial 64K) compress 2');
    ctx_ddl.set_attribute('textstore', 'P_TABLE_CLAUSE','tablespace CAPT_DATA storage (initial 64K)');
end;
create index capone.IX_test_sh4  on test_sh4 (text3)
indextype is ctxsys.context
parameters
    ('datastore test_mcd
      lexer          test_lex1
      section group  test_sg 
       wordlist SUBSTRING_PREF 
       SYNC ( ON COMMIT)
       storage textstore
       MEMORY 50M '
-- In normal scenario colour doesn't come up
SQL> set lines 100;
SQL>    SELECT SCORE(1) SCORE, T.*
  2   FROM   test_sh4 t
  3   WHERE  CONTAINS
  4           (text3,
  5            '<query>
  6               <textquery>
  7                 <progression>
  8                   <seq> color within text2</seq>
  9                 </progression>
10               </textquery>
11               <score datatype="FLOAT" algorithm="default"/>
12             </query>',
13            1) > 0
14   ORDER  BY score(1) DESC;
     SCORE TEXT1                TEXT2                T
    3.9031 color                color  labor         y
-- If we use stem operator it comes up but it will also retrun lot of other irelevant results
SQL>    SELECT SCORE(1) SCORE, T.*
  2   FROM   test_sh4 t
WHERE  CONTAINS
  3    4              (text3,
  5            '<query>
  6               <textquery>
  7                 <progression>
  8                   <seq> $color within text2</seq>
  9                 </progression>
10               </textquery>
11               <score datatype="FLOAT" algorithm="default"/>
12             </query>',
13            1) > 0
14   ORDER  BY score(1) DESC;
     SCORE TEXT1                TEXT2                T
    3.9031 colour               colour  labour       y
    3.9031 color                color  labor         y
          Is there any way apart from stem operators to get these words.