在 CLOB 列上创建索引

Question

我有一个表interventi，它有这个结构

describe interventi;
Name                           Null     Type
------------------------------ -------- -----------------------
DATAORA                        NOT NULL TIMESTAMP(6)
PARLAMENTARE                   NOT NULL VARCHAR2(16)
TESTO                          NOT NULL CLOB()

其中归档的 dataora 是主键。我用一行填充了这张表

DATAORA                         PARLAMENTARE     TESTO
------------------------------- ---------------- ------------------------------- 
05-JUL-18 12.00.00.000000000 AM MRTMRZ           (CLOB) PIPPO PLUTO PAPERINO

1 rows selected

现在，我想在字段 testo 上创建一个索引

create index idx_testo_interventi
on interventi(testo) indextype is
ctxsys.context;

但是

Error starting at line 1 in command:
create index idx_testo_interventi
on interventi(testo) indextype is
ctxsys.context
Error at Command Line:1 Column:13
Error report:
SQL Error: ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-20000: Oracle Text error:
DRG-10528: primary keys of type TIMESTAMP(6) are not allowed
ORA-06512: at "CTXSYS.DRUE", line 160
ORA-06512: at "CTXSYS.TEXTINDEXMETHODS", line 366
29855. 00000 -  "error occurred in the execution of ODCIINDEXCREATE routine"
*Cause:    Failed to successfully execute the ODCIIndexCreate routine.
*Action:   Check to see if the routine has been coded correctly.

如何创建索引？

Answer 1

稍作调整可能会有所帮助。

以下是不起作用的：

SQL> create table interventi
  2    (dataora      timestamp(6) primary key,
  3     parlamentare varchar2(16),
  4     testo        clob);

Table created.

SQL> create index idx_testo_interventi on interventi (testo)
  2    indextype is ctxsys.context;
create index idx_testo_interventi on interventi (testo)
*
ERROR at line 1:
ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-20000: Oracle Text error:
DRG-10528: primary keys of type TIMESTAMP(6) are not allowed
ORA-06512: at "CTXSYS.DRUE", line 160
ORA-06512: at "CTXSYS.TEXTINDEXMETHODS", line 366

你可以这样做：

• 包括将用作主键的附加列（在我的示例中为 ID）
• 使用序列填充触发器
• 到目前为止，您用作主键的列设置为 unique not null（这将就好像它是主键一样 - 没有重复，没有 NULL 值）

.

SQL> drop table interventi;

Table dropped.

SQL> create table interventi
  2    (id number    primary key,
  3     dataora      timestamp(6) unique not null,
  4     parlamentare varchar2(16),
  5     testo        clob);

Table created.

SQL> create sequence seqa;

Sequence created.

SQL> create or replace trigger trg_bi_inter
  2    before insert on interventi
  3    for each row
  4  begin
  5    :new.id := seqa.nextval;
  6  end;
  7  /

Trigger created.

SQL> create index idx_testo_interventi on interventi (testo)
  2    indextype is ctxsys.context;

Index created.

SQL>

[编辑：如何运行 CTX_DDL]

您必须获得运行它的权限。方法如下：以特权用户身份（SYS 是其中之一，如果您没有创建另一个用户）和该软件包上的 GRANT EXECUTE 连接到将要使用它的用户。

看看这个例子：起初，它不起作用（正如你已经注意到的那样）：

SQL> exec ctx_ddl.sync_index('idx_testo_interventi');
BEGIN ctx_ddl.sync_index('idx_testo_interventi'); END;

      *
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00201: identifier 'CTX_DDL' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored

以SYS（或其他特权用户，如果你有的话）连接：

SQL> connect sys@xe as sysdba
Enter password:
Connected.
SQL> grant execute on ctx_ddl to scott;

Grant succeeded.

返回interventi 表（和索引）的所有者：

SQL> connect scott@xe
Enter password:
Connected.
SQL> exec ctx_ddl.sync_index('idx_testo_interventi');

PL/SQL procedure successfully completed.

SQL>

似乎还可以。