Is the word "text" an operator or reserved word in Oracle Text?

Question

DB: Oracle 10.2.0.3.0
I have created a CONTEXT index on a table which uses a Multi-Column Datastore on two columns (text and keywords)
When I perform this query, I'm getting back every row in the table even though none contain a value of "text" within the TEXT or KEYWORDS columns.
SELECT *
FROM tb_rh_links
WHERE CONTAINS(search_column, 'text') > 0
** UPDATE ** it does the same things when searching for word "keywords." I'm beginning to think it has something to do with the section groups...
SELECT *
FROM tb_rh_links
WHERE CONTAINS(search_column, 'keywords') > 0
Here is how the index and multi-column datastore is setup:
BEGIN
ctx_ddl.create_preference ('rh_lex', 'basic_lexer');
ctx_ddl.set_attribute ('rh_lex', 'index_stems', 'english');
ctx_ddl.create_preference('rh_links_mcds', 'MULTI_COLUMN_DATASTORE');
ctx_ddl.set_attribute('rh_links_mcds', 'columns', 'text, keywords');
END;
BEGIN
ctx_ddl.create_section_group('rh_links_sg','basic_section_group');
ctx_ddl.add_field_section(group_name => 'rh_links_sg',
section_name => 'text',
tag => 'text');
ctx_ddl.add_field_section(group_name => 'rh_links_sg',
section_name => 'keywords',
tag => 'keywords');
END;
CREATE INDEX TB_RH_LINKS_IDX5 ON TB_RH_LINKS (KEYWORDS)
INDEXTYPE IS ctxsys.CONTEXT
PARAMETERS('datastore rh_links_mcds section group rh_links_sg');
Edited by: Dishoom on Apr 20, 2009 11:07 AM

Answer 1

When you create a multi_column_datastore without specifying a delimiter, by default the column names are tokenized and indexed. If you specify the newline delimiter, then the column names are not tokenized. Or, once you have created sections and used the section group in your parameters, then the column names are not tokenized. You may have created your multi_column_datastore, then created your index, tokenized the column names, then added the sections, but the tokenized column names weren't dropped until you recreated the index. Please see the demonstration below.
SCOTT@orcl_11g> CREATE TABLE tb_rh_links
  2    (text            VARCHAR2(10),
  3       keywords       VARCHAR2(10),
  4       search_column  VARCHAR2( 1))
  5  /
Table created.
SCOTT@orcl_11g> INSERT ALL
  2  INTO tb_rh_links VALUES ('word1', 'word2', null)
  3  INTO tb_rh_links VALUES ('word3', 'word4', null)
  4  SELECT * FROM DUAL
  5  /
2 rows created.
SCOTT@orcl_11g> BEGIN
  2    ctx_ddl.create_preference ('rh_lex', 'basic_lexer');
  3    ctx_ddl.set_attribute ('rh_lex', 'index_stems', 'english');
  4    ctx_ddl.create_preference('rh_links_mcds', 'MULTI_COLUMN_DATASTORE');
  5    ctx_ddl.set_attribute('rh_links_mcds', 'columns', 'text, keywords');
  6  END;
  7  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11g> CREATE INDEX TB_RH_LINKS_IDX5 ON TB_RH_LINKS (search_column)
  2  INDEXTYPE IS ctxsys.CONTEXT
  3  PARAMETERS('datastore rh_links_mcds')
  4  /
Index created.
SCOTT@orcl_11g> -- the column names are tokenized:
SCOTT@orcl_11g> COLUMN token_text FORMAT A10
SCOTT@orcl_11g> SELECT token_text, token_first, token_last, token_count
  2  FROM   dr$tb_rh_links_idx5$i
  3  /
TOKEN_TEXT TOKEN_FIRST TOKEN_LAST TOKEN_COUNT
KEYWORDS             1          2           2
TEXT                 1          2           2
WORD1                1          1           1
WORD2                1          1           1
WORD3                2          2           1
WORD4                2          2           1
6 rows selected.
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'text') > 0
  4  /
TEXT       KEYWORDS   S
word1      word2
word3      word4
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'keywords') > 0
  4  /
TEXT       KEYWORDS   S
word1      word2
word3      word4
SCOTT@orcl_11g> -- if you use the newline delimieter, the column names are not tokenized:
SCOTT@orcl_11g> BEGIN
  2    CTX_DDL.SET_ATTRIBUTE ('rh_links_mcds', 'DELIMITER', 'NEWLINE');
  3  END;
  4  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11g> DROP INDEX tb_rh_links_idx5
  2  /
Index dropped.
SCOTT@orcl_11g> CREATE INDEX TB_RH_LINKS_IDX5 ON TB_RH_LINKS (search_column)
  2  INDEXTYPE IS ctxsys.CONTEXT
  3  PARAMETERS('datastore rh_links_mcds')
  4  /
Index created.
SCOTT@orcl_11g> SELECT token_text, token_first, token_last, token_count
  2  FROM   dr$tb_rh_links_idx5$i
  3  /
TOKEN_TEXT TOKEN_FIRST TOKEN_LAST TOKEN_COUNT
WORD1                1          1           1
WORD2                1          1           1
WORD3                2          2           1
WORD4                2          2           1
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'text') > 0
  4  /
no rows selected
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'keywords') > 0
  4  /
no rows selected
SCOTT@orcl_11g> -- or, with the section groups, the column names are not tokenized:
SCOTT@orcl_11g> BEGIN
  2    -- return to default:
  3    CTX_DDL.SET_ATTRIBUTE ('rh_links_mcds', 'DELIMITER', 'COLUMN_NAME_TAG');
  4  END;
  5  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11g> BEGIN
  2    ctx_ddl.create_section_group('rh_links_sg','basic_section_group');
  3    ctx_ddl.add_field_section(group_name => 'rh_links_sg',
  4        section_name => 'text',
  5        tag => 'text');
  6    ctx_ddl.add_field_section(group_name => 'rh_links_sg',
  7        section_name => 'keywords',
  8        tag => 'keywords');
  9  END;
10  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11g> DROP INDEX tb_rh_links_idx5
  2  /
Index dropped.
SCOTT@orcl_11g> CREATE INDEX TB_RH_LINKS_IDX5 ON TB_RH_LINKS (search_column)
  2  INDEXTYPE IS ctxsys.CONTEXT
  3  PARAMETERS('datastore rh_links_mcds section group rh_links_sg')
  4  /
Index created.
SCOTT@orcl_11g> SELECT token_text, token_first, token_last, token_count
  2  FROM   dr$tb_rh_links_idx5$i
  3  /
TOKEN_TEXT TOKEN_FIRST TOKEN_LAST TOKEN_COUNT
WORD1                1          1           1
WORD2                1          1           1
WORD3                2          2           1
WORD4                2          2           1
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'text') > 0
  4  /
no rows selected
SCOTT@orcl_11g> SELECT *
  2  FROM tb_rh_links
  3  WHERE CONTAINS(search_column, 'keywords') > 0
  4  /
no rows selected
SCOTT@orcl_11g>