OTI index with documents

Question

Hi,
Could you please guide me whether the following approch is right way to implement my requirment, I'm working for one of the fuzzy search requiremnet, My table contains 100 million rows with varchar2 datatype, for this i have been created the following steps,
1. Convert the table data in to XML documents with help of following pl/sql procedure
CREATE OR REPLACE PACKAGE Chrdscr IS
p_dir_name varchar2(13) := '/opt/app/log/';
procedure OpenXmlFile(p_dir_name varchar2);
END Chrdscr;
CREATE OR REPLACE PACKAGE Chrdscr IS
p_dir_name varchar2(13) := '/opt/app/log/';
procedure OpenXmlFile(p_dir_name varchar2);
END Chrdscr;
create or replace package body Chrdscr is
v_FILENAME varchar2(30);
f_XML_FILE UTL_FILE.file_type;
procedure OpenXmlFile(p_dir_name varchar2) is
v_record_data varchar2(4000) := null;
v_DSCR varchar2(4000) := null;
cursor orders_cursor is
select t.dscr
from CHR_DSCR_T t;
begin
--v_FILENAME := TO_CHAR(SYSDATE, 'DDMMYYYYHH24MI') || '.xml';
v_FILENAME := 'chrdscr.xml';
f_XML_FILE := UTL_FILE.fopen('DATA_PUMP_DIR', v_FILENAME, 'W');
v_RECORD_DATA := '<?xml version="1.0" encoding="UTF-8"?>';
UTL_FILE.put_line(f_XML_FILE, v_RECORD_DATA);
open orders_cursor;
loop
fetch orders_cursor
into v_DSCR;
EXIT WHEN orders_cursor%NOTFOUND;
UTL_FILE.put_line(f_XML_FILE,
' <DSCR>' || v_DSCR || '</DSCR>');
end loop;
close orders_cursor;
UTL_FILE.FCLOSE(f_XML_FILE);
EXCEPTION
WHEN UTL_FILE.INTERNAL_ERROR THEN
raise_application_error(-20500,
'Cannot open file :' || v_FILENAME ||
', internal error; code:' || sqlcode ||
',message:' || sqlerrm);
WHEN UTL_FILE.INVALID_OPERATION THEN
raise_application_error(-20501,
'Cannot open file :' || v_FILENAME ||
', invalid operation; code:' || sqlcode ||
',message:' || sqlerrm);
WHEN UTL_FILE.INVALID_PATH THEN
raise_application_error(-20502,
'Cannot open file :' || v_FILENAME ||
', invalid path; code:' || sqlcode ||
',message:' || sqlerrm);
WHEN UTL_FILE.WRITE_ERROR THEN
raise_application_error(-20503,
'Cannot write to file :' || v_FILENAME ||
', write error; code:' || sqlcode ||
',message:' || sqlerrm);
end;
end Chrdscr;
PL/SQL procedure successfully completed.
2. The XML document created in the directory, after that i have created one table
CREATE TABLE testtab
(id NUMBER,
     docs VARCHAR2 (30))
Table created.
INSERT INTO testtab     VALUES (1, 'chrdscr.xml')
1 row created.
3. Context type index also created for the XML document
CREATE INDEX otiind ON testtab (docs)
INDEXTYPE IS CTXSYS.CONTEXT
PARAMETERS ('DATASTORE otipref')
Index created.
SQL> SELECT token_text FROM dr$otiind$i
2 ;
TOKEN_TEXT
1.0
1888
13654
125678.6
888
999999
DATA
DIRECT
ENCODING
UTF
VERSION
TOKEN_TEXT
XML
12 rows selected.
5. then i executed the follwing step
begin
chrdscr.OpenXmlFile('opt/app/log/');
end;
SELECT id FROM mytab
2 WHERE CONTAINS (docs, 'data') > 0
3 /
ID
1
Could you please advice me whether this approch will satify the fuzzy search requirment? your help is very much helpful to implement this.

Answer 1

I don't know why you insist on adding the extra unnecessary step of xml. What do you expect to gain by using xml? There are various ways to create and index your xml. The example below is just one of many. You can find other methods and examples in the online documentation. As you can see below, there is nothing gained by adding the xml. If you want sections, you can create a multi_column_datastore without the xml, but still have your separate columns to select from.
SCOTT@orcl_11gR2> CREATE TABLE chr_dscr_t
  2    (CHR_DSCR_ID  NUMBER           NOT NULL,
  3       CHR_ID          NUMBER           NOT NULL,
  4       LANG_ID      NUMBER           NOT NULL,
  5       DSCR_ID      NUMBER           NOT NULL,
  6       DSCR          VARCHAR2(4000 CHAR),
  7       TRANS_ST     VARCHAR2(1 CHAR)      NOT NULL,
  8       CRTD_BY      VARCHAR2(50 CHAR)      NOT NULL,
  9       CRTD_DTTM    DATE           NOT NULL,
10       UPD_BY          VARCHAR2(50 CHAR)      NOT NULL,
11       UPD_DTTM     DATE           NOT NULL,
12       LCK_NUM      NUMBER           NOT NULL)
13  /
Table created.
SCOTT@orcl_11gR2> BEGIN
  2    CTX_DDL.CREATE_PREFERENCE ('chr_dscr_wordlist', 'BASIC_WORDLIST');
  3    CTX_DDL.SET_ATTRIBUTE ('chr_dscr_wordlist', 'FUZZY_MATCH', 'AUTO');
  4    CTX_DDL.SET_ATTRIBUTE ('chr_dscr_wordlist', 'FUZZY_SCORE', 0);
  5    CTX_DDL.SET_ATTRIBUTE ('chr_dscr_wordlist', 'FUZZY_NUMRESULTS', 5000);
  6  END;
  7  /
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2> INSERT INTO chr_dscr_t VALUES
  2    (1, 2, 3, 4, 'This is a test record.', 'a', 'b', SYSDATE, 'c', SYSDATE, 5)
  3  /
1 row created.
SCOTT@orcl_11gR2> INSERT INTO chr_dscr_t VALUES
  2    (2, 3, 4, 5, 'tests tests tests', 'c', 'd', SYSDATE, 'e', SYSDATE, 6)
  3  /
1 row created.
SCOTT@orcl_11gR2> COMMIT
  2  /
Commit complete.
SCOTT@orcl_11gR2> CREATE TABLE testtab
  2    (id   NUMBER,
  3       docs CLOB)
  4  /
Table created.
SCOTT@orcl_11gR2> INSERT INTO testtab (id, docs)
  2  SELECT chr_dscr_id,
  3           DBMS_XMLGEN.GETXML
  4             ('SELECT *
  5            FROM   chr_dscr_t
  6            WHERE  chr_dscr_id = ' || chr_dscr_id)
  7  FROM   chr_dscr_t
  8  /
2 rows created.
SCOTT@orcl_11gR2> SELECT * FROM testtab
  2  /
        ID
DOCS
         1
<?xml version="1.0"?>
<ROWSET>
<ROW>
  <CHR_DSCR_ID>1</CHR_DSCR_ID>
  <CHR_ID>2</CHR_ID>
  <LANG_ID>3</LANG_ID>
  <DSCR_ID>4</DSCR_ID>
  <DSCR>This is a test record.</DSCR>
  <TRANS_ST>a</TRANS_ST>
  <CRTD_BY>b</CRTD_BY>
  <CRTD_DTTM>21-DEC-10</CRTD_DTTM>
  <UPD_BY>c</UPD_BY>
  <UPD_DTTM>21-DEC-10</UPD_DTTM>
  <LCK_NUM>5</LCK_NUM>
</ROW>
</ROWSET>
         2
<?xml version="1.0"?>
<ROWSET>
<ROW>
  <CHR_DSCR_ID>2</CHR_DSCR_ID>
  <CHR_ID>3</CHR_ID>
  <LANG_ID>4</LANG_ID>
  <DSCR_ID>5</DSCR_ID>
  <DSCR>tests tests tests</DSCR>
  <TRANS_ST>c</TRANS_ST>
  <CRTD_BY>d</CRTD_BY>
  <CRTD_DTTM>21-DEC-10</CRTD_DTTM>
  <UPD_BY>e</UPD_BY>
  <UPD_DTTM>21-DEC-10</UPD_DTTM>
  <LCK_NUM>6</LCK_NUM>
</ROW>
</ROWSET>
2 rows selected.
SCOTT@orcl_11gR2> CREATE INDEX chr_dscr_t_dscr_idx
  2  ON testtab (docs)
  3  INDEXTYPE IS CTXSYS.CONTEXT
  4  PARAMETERS
  5    ('WORDLIST     chr_dscr_wordlist
  6        SYNC          (ON COMMIT)
  7        SECTION GROUP     CTXSYS.AUTO_SECTION_GROUP')
  8  /
Index created.
SCOTT@orcl_11gR2> VARIABLE criteria VARCHAR2(100)
SCOTT@orcl_11gR2> VARIABLE page NUMBER
SCOTT@orcl_11gR2> EXEC :criteria := 'tests'
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2> EXEC :page := 1
PL/SQL procedure successfully completed.
SCOTT@orcl_11gR2> COLUMN criteria_in_context FORMAT A45 WORD_WRAPPED
SCOTT@orcl_11gR2> SELECT rank, criteria_in_context
  2  FROM   (SELECT SCORE (1) rank,
  3                CTX_DOC.SNIPPET
  4                  ('chr_dscr_t_dscr_idx',
  5                   ROWID,
  6                   'FUZZY (' || :criteria || ') WITHIN dscr')
  7                  AS criteria_in_context,
  8                ROW_NUMBER () OVER (ORDER BY SCORE (1) DESC) rn
  9            FROM   testtab
10            WHERE  CONTAINS (docs, 'FUZZY (' || :criteria || ') WITHIN dscr', 1) > 0
11            ORDER  BY SCORE (1) DESC)
12  WHERE  rn BETWEEN ((:page - 1) * 20) + 1 AND :page * 20
13  /
      RANK CRITERIA_IN_CONTEXT
        12 2
           3
           4
           5
           <b>tests</b> <b>tests</b> <b>tests</b>
           c
           d
           21-DEC-10
           e
           21-DEC
         4 1
           2
           3
           4
           This is a <b>test</b> record.
           a
           b
           21-DEC-10
           c
           21
2 rows selected.
SCOTT@orcl_11gR2>