Oracle文本ctxrule-匹配: 特殊单词工作和不工作？

大家好，

我使用CTXRULE对一些文本进行分类，但是AB & B工作而AT&T不工作。请在这方面支持我:

这是我的搜索文本

SQL> select text from test_lexer_special;

TEXT
--------------------
AB&B
{AT&T}
AT&T

SQL>

我如何创建索引

SQL> EXEC CTX_DDL.CREATE_INDEX_SET('test_ctxrule_1');    
PL/SQL procedure successfully completed.

SQL> EXEC CTX_DDL.CREATE_PREFERENCE ('testmy_lexer', 'BASIC_LEXER');    
PL/SQL procedure successfully completed.

SQL> EXEC CTX_DDL.SET_ATTRIBUTE ('testmy_lexer', 'PRINTJOINS', '&');    
PL/SQL procedure successfully completed.

SQL> CREATE INDEX test_ctxrule_index1 ON test_lexer_special (text)
  2  INDEXTYPE IS CTXSYS.CTXRULE  
  3  PARAMETERS ('INDEX SET test_ctxrule_1 LEXER testmy_lexer STOPLIST CTXSYS.EMPTY_STOPLIST');

Index created.

SQL>

这很管用

SQL> SELECT *  FROM    test_lexer_special WHERE MATCHES(text, 'ab&b')> 0;

TEXT
--------------------
AB&B

SQL>

这不起作用

SQL> SELECT *  FROM    test_lexer_special WHERE MATCHES(text, 'at&t')> 0;

no rows selected

SQL> select token_text,token_extra from DR$test_ctxrule_index1$I;

TOKEN_TEXT           TOKEN_EXTRA
-------------------- --------------------
AB                   {B}

SQL> 

谢谢。

AT仍然是停止名单的一部分!您可以通过使用ctx_report.describe_index报告索引来看到这一点:

create table test_lexer_special (
  text varchar2(30)
);

set define off
insert into test_lexer_special values ('AB&B');
insert into test_lexer_special values ('{AT&T}');
insert into test_lexer_special values ('AT&T');

CREATE INDEX test_ctxrule_index1 ON test_lexer_special (text) INDEXTYPE IS CTXSYS.CTXRULE  
  PARAMETERS ('INDEX SET test_ctxrule_1 LEXER testmy_lexer STOPLIST CTXSYS.EMPTY_STOPLIST');

set long 2000000000
set head off
set pagesize 10000
select ctx_report.describe_index('TEST_CTXRULE_INDEX1') from dual;

===========================================================================
                             INDEX DESCRIPTION
===========================================================================
index name:                    "CHRIS"."TEST_CTXRULE_INDEX1"
index id:                      1284
index type:                    ctxrule

base table:                    "CHRIS"."TEST_LEXER_SPECIAL"
primary key column:            
text column:                   TEXT
text column type:              VARCHAR2(30)
language column:               
format column:                 
charset column:                
configuration column:          
Query Stats Enabled:           NO


status:                        INDEXED
full optimize token:           
full optimize count:           
docid count:                   3
nextid:                        4

===========================================================================
                               INDEX OBJECTS
===========================================================================
datastore:                     DIRECT_DATASTORE

filter:                        NULL_FILTER

section group:                 NULL_SECTION_GROUP

lexer:                         BASIC_LEXER

wordlist:                      BASIC_WORDLIST
   stemmer:                       ENGLISH
   fuzzy_match:                   GENERIC

stoplist:                      BASIC_STOPLIST
   stop_word:                     Mr
   stop_word:                     Mrs
   stop_word:                     Ms
   stop_word:                     a
   stop_word:                     all
   stop_word:                     almost
   stop_word:                     also
   stop_word:                     although
   stop_word:                     an
   stop_word:                     and
   stop_word:                     any
   stop_word:                     are
   stop_word:                     as
   stop_word:                     at
... etc. ...

那么为什么会发生这种情况？你指定了一个空的停止名单，对吗？

你还指定了一个索引集。这些仅适用于CTXCAT索引。你正在使用CTXRULE。不幸的是，这不会引发异常...

单独指定停止列表，一切都将是hunky dory:

drop INDEX test_ctxrule_index1;
CREATE INDEX test_ctxrule_index1 ON test_lexer_special (text) INDEXTYPE IS CTXSYS.CTXRULE  
  PARAMETERS ('STOPLIST CTXSYS.EMPTY_STOPLIST');
  
SELECT * FROM test_lexer_special WHERE MATCHES(text, 'at&t',1)> 0;

TEXT    
{AT&T}  
AT&T