你需要在這裏展示一些代碼。
以下是創建一個屬性的xmlindex
(及其子節點)的例子:
SQL> create table xmltest (a xmltype);
Table created.
SQL> insert into xmltest values ('<root>
2 <a test="foo" test2="asd">
3 <b>hi</b>
4 </a>
5 <a test="foo2" test2="asd2">hi</a>
6 </root>');
1 row created.
SQL> commit;
Commit complete.
SQL> create index test_xmlindex on xmltest (a)
2 indextype is XDB.XMLIndex
3 parameters ('paths (include (/root/a/@test))');
Index created.
SQL> set pagesize 100 lines 200 heading off
SQL> explain plan for select * from xmltest where xmlexists('/root/a[@test="foo"]' passing a);
Explained.
SQL> select * from table(dbms_xplan.display());
Plan hash value: 2925043098
-------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2026 | 6 (17)| 00:00:01 |
| 1 | NESTED LOOPS | | 1 | 2026 | 6 (17)| 00:00:01 |
| 2 | VIEW | VW_SQ_1 | 1 | 12 | 4 (0)| 00:00:01 |
| 3 | HASH UNIQUE | | 1 | 5046 | | |
| 4 | NESTED LOOPS | | | | | |
| 5 | NESTED LOOPS | | 1 | 5046 | 4 (0)| 00:00:01 |
|* 6 | TABLE ACCESS BY INDEX ROWID| SYS82641_TEST_XMLIN_PATH_TABLE | 1 | 3524 | 2 (0)| 00:00:01 |
|* 7 | INDEX RANGE SCAN | SYS82641_TEST_XMLIN_VALUE_IX | 1 | | 1 (0)| 00:00:01 |
|* 8 | INDEX RANGE SCAN | SYS82641_TEST_XMLIN_PIKEY_IX | 1 | | 1 (0)| 00:00:01 |
|* 9 | TABLE ACCESS BY INDEX ROWID | SYS82641_TEST_XMLIN_PATH_TABLE | 1 | 1522 | 2 (0)| 00:00:01 |
| 10 | TABLE ACCESS BY USER ROWID | XMLTEST | 1 | 2014 | 1 (0)| 00:00:01 |
-------------------------------------------------------------------------------------------------------------------
通過索引paths (include (/root/a/@test))
它將包含在索引中的孩子<b>
節點,但不是test2
屬性。如果省略/@test
,則索引也會獲得test2
屬性。
感謝您的示例。這給了我一個很好的起點。 – 2013-03-22 04:45:11