Oracle

Question

我在列 (DYNAMIC_SQL) 中包含一系列 'dynamic' SQL 查询，'dynamic' 查询本身相当基础；

例如 SELECT ROWID AS RECORD_ID, COLUMN_1 AS STR_VALUE, '-Undefined-' AS STR_IDENTIFIER_VALUE, 'DS_1319' AS DS_TABLE_NAME FROM DS_1319

然后我结合使用 XMLTABLE 和 GETXML 来提取和显示结果。

但是，即使查询运行并按预期运行，我注意到性能非常差（注意：DS_1319 的行数为；13,939）。

我使用的查询如下：

SELECT
  T1.*,
  T2.RECORD_ID,
  T2.STR_VALUE,
  T2.STR_IDENTIFIER_VALUE
FROM
  CP_RDN_IN_DYNAMIC_SQL_TMP T1,
  XMLTABLE('/ROWSET /ROW' 
           PASSING XMLTYPE(DBMS_XMLGEN.GETXML(T1.DYNAMIC_SQL)) 
           COLUMNS RECORD_ID VARCHAR2(255) PATH 'RECORD_ID',
                   STR_VALUE VARCHAR2(255) PATH 'STR_VALUE',
                   STR_IDENTIFIER_VALUE VARCHAR2(255) PATH 'STR_IDENTIFIER_VALUE',
                   DS_TABLE_NAME VARCHAR2(255) PATH 'DS_TABLE_NAME') T2
WHERE
  T1.DS_TABLE_NAME = T2.DS_TABLE_NAME

注意：DYNAMIC_SQL 列定义如下；

'SELECT ROWID AS RECORD_ID, '||
        T1.FIELD_NAME||' AS STR_VALUE, '||
        T1.IDENTIFIER_FIELD_NAME||' AS STR_IDENTIFIER_VALUE, '''||
        T1.DS_TABLE_NAME||''' AS DS_TABLE_NAME 
 FROM'||T1.DS_TABLE_NAME AS DYNAMIC_SQL

以下是一小部分数据；

<?xml version="1.0"?>
<ROWSET>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAA</RECORD_ID>
  <STR_VALUE>ORACLE</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAB</RECORD_ID>
  <STR_VALUE>Oracle</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAC</RECORD_ID>
  <STR_VALUE>Oracle 9i</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAD</RECORD_ID>
  <STR_VALUE>Oracle 11g</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAE</RECORD_ID>
  <STR_VALUE>Oracle CRM</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAF</RECORD_ID>
  <STR_VALUE>oracle 10g</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAG</RECORD_ID>
  <STR_VALUE>ORACLE, XE</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAH</RECORD_ID>
  <STR_VALUE>XE</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAI</RECORD_ID>
  <STR_VALUE>MS Windows</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAJ</RECORD_ID>
  <STR_VALUE>Microsoft Windows Vista</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAK</RECORD_ID>
  <STR_VALUE>Vista</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAL</RECORD_ID>
  <STR_VALUE>MSOFT Win Vista</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAM</RECORD_ID>
  <STR_VALUE>Microsoft Office</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAN</RECORD_ID>
  <STR_VALUE>MS SQL Server</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAO</RECORD_ID>
  <STR_VALUE>VISTA MS WINDOWS</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAP</RECORD_ID>
  <STR_VALUE>Windows vista</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAQ</RECORD_ID>
  <STR_VALUE>Microsoft Windows 2000</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
 <ROW>
  <RECORD_ID>AAAGU2AABAAAShJAAR</RECORD_ID>
  <STR_VALUE>Macromedia</STR_VALUE>
  <STR_IDENTIFIER_VALUE>-Undefined-</STR_IDENTIFIER_VALUE>
  <DS_TABLE_NAME>DS_1319</DS_TABLE_NAME>
 </ROW>
</ROWSET>

我相当肯定有一种更有效的方法可以达到预期的结果，所以如果有任何脑洞大开的人提出一些意见/建议，我们将不胜感激（我愿意接受; 纯 SQL, PL/SQL, 等).

非常感谢。

Answer 1

我看不出有什么理由把结果转成XML，直接make dynamic SELECT就可以了

   cur SYS_REFCURSOR;
BEGIN
DYNAMIC_SQL := 'SELECT ROWID AS RECORD_ID, '||
        T1.FIELD_NAME||' AS STR_VALUE, '||
        T1.IDENTIFIER_FIELD_NAME||' AS STR_IDENTIFIER_VALUE, '''||
        T1.DS_TABLE_NAME||''' AS DS_TABLE_NAME 
 FROM'||T1.DS_TABLE_NAME;

OPEN CURSOR cur FOR DYNAMIC_SQL;
FETCH ...

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