XML Extender

The override parameter's description for the following stored procedures has changed:

Parameters

Table 42. Override parameter for the dxxGenXML, dxxGenXMLClob, dxxRetrieveXML, and dxxRetrieveXMLClob stored procedures
Parameter	Description	IN/OUT Parameter
`override`	Overrides the condition in the DAD file. The input value is based on the `overrideType`. NO_OVERRIDE: A NULL string. SQL_OVERRIDE: A valid SQL statement. Using this `overrideType` requires that SQL mapping is used in the DAD file. The input SQL statement overrides the SQL_stmt in the DAD file. XML_OVERRIDE: A string that contains one or more expressions that are separated by the word AND. Using this `overrideType` requires that RDB_node mapping is used in the DAD file.	IN

Decomposing XML documents into DB2 UDB data

Decomposition uses RDB_node mapping to specify how an XML document is decomposed into DB2 UDB tables by extracting the element and attribute values and storing them in table rows. The values from each XML document are stored in one or more DB2 UDB tables. Each table can have a maximum of 10240 rows decomposed from each document.

For example, if an XML document is decomposed into five tables, each of the five tables can have up to 10240 rows for that particular document. If the table has rows for multiple documents, it can have up to 10240 rows for each document.

Using multiple-occurring elements (elements with location paths that can occur more than once in the XML structure) affects the number of rows . For example, a document that contains an element <Part> that occurs 20 times, might be decomposed as 20 rows in a table. When using multiple occurring elements, consider that a maximum of 10240 rows can be decomposed into one table from a single document.

Decomposing documents larger than 1 MB

You do not need to drop and recreate the stored procedure dxxShredXML to decompose documents that are larger than 1 MB. To decompose documents that are larger than 1 MB, invoke the stored procedure dxxShredXML100MB, which can shred documents up to 100 MB. Although dxxShredXML100MB can handle large documents, you might need to increase other resources for the stored procedure to complete successfully. To invoke the stored procedure through the sample program dxxshrd, use the new flag "-large". For example:

If your version of DB2 Universal Database^(TM) is earlier than Version 8 FixPak 6, you must run dxxMigv to migrate XML Extender to the current level to run the new stored procedure.

Configuring MQ XML UDFs with XML Extender

You must configure and enable MQ XML user-defined functions (UDFs) before you can use them.

Prerequisites

Install the UDFs by following the procedure in the "Installing DB2^(R) WebSphere^(R) MQ functions" topic, which is found either in the Information Center or the IBM^(R) DB2 Information Integrator Application Developer's Guide.

Procedure

To configure and enable MQ XML UDFs with XML Extender:

Open a DB2 command prompt window.
Connect to the database that will use the MQ XML UDFs by entering the following command:
```
db2 connect to <database>
```
Change to the bnd directory within the path where you installed DB2 Universal Database, such as:
- SQLLIB/bnd (Linux^(TM) and UNIX^(R))
- C:\Program Files\IBM\SQLLIB\bnd (Windows^(R))
Bind the database to XML Extender using the following command:
```
db2 bind @dbxxbind.lst
```
Bind the database for XML Extender to use the MQ XML UDFs using the following command:
```
db2 bind mqxml.bnd
```
Bind the database to the CLI using the following command:
```
db2 bind @db2cli.lst
```

XML Extender environment variable DB2DXX_MIN_TMPFILE_SIZE

DB2 XML Extender can place large documents in temporary files to avoid using a great amount of memory during processing. On systems with large amounts of physical memory, you can avoid moving documents to temporary files, reducing the amount of Input/Output activity. The environment variable DB2DXX_MIN_TMPFILE_SIZE instructs XML Extender to use memory buffers, instead of temporary files, for processing documents smaller than the specified value. The variable is applicable only on the server. If multiple physical nodes participate in a partitioned environment, the variable can be set differently on each node, accurately reflecting the amount of memory installed on each computer. If the environment variable is not set, documents larger than 128 KB will automatically be placed into temporary files during processing. Documents smaller than 128 KB will be processed in memory.

DB2XML.XMLVarchar UDT redefinition