PK90040: Enabling APAR to remove the 50M bytes limitation on XML schema

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DK1256 enabling APAR
  

Local fix

• No Work Around
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: DB2 R910 Users of DSN_XMLVALIDATE.           *
  ****************************************************************
  * PROBLEM DESCRIPTION: Current DB2 9 for z/OS user-defined     *
  *                      function DSN_XMLVALIDATE cannot         *
  *                      validate an XML document larger than    *
  *                      50M bytes. Currently, the XML parser    *
  *                      process invoked through XML validation  *
  *                      does not take advantage of IBM          *
  *                      Specialty Engines (zIIP or zAAP).       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The current DSN_XMLVALIDATE user-defined function is
  implemented as a C stored procedure executing in the WLM
  address space. This limits the size of the XML document to be
  validated to 50M bytes. Also, the XML parser process invoked
  through XML validation does not take advantage of IBM
  Specialty Engines (zIIP or zAAP).
  
  To support validation of an XML document larger than
  50M bytes and take advantage of IBM Specialty Engines
  (zIIP or zAAP), a new SQL scalar function, DSN_XMLVALIDATE,
  will be added. The new function can validate up to a maximum
  length of 2G-1 bytes of XML data, depending on system
  resources.
  
  To use this new scalar function, users need to
  1. ensure the z/OS OS level is R1.9 with PTF OA25903 or R1.10.
     If you try to use this new function without this z/OS
     level, DB2 will issue SQLCODE904: reason-code 00D50005,
     resource-type 00003000, resource-name z/OS 1.9 or 1.10 XML
     System Services.
  
  2. run the following command after each ipl
     SETPROG LPA,ADD,MODNAME=(GXLIMODV),DSNAME=SYS1.SIEALNKE
     Otherwise, SYSIBM.DSN_XMLVALIDATE will fail with SQLCODE904
     with RC00D50005.
  
  3. qualify DSN_XMLVALIDATE explicitly with
     SYSIBM. When DSN_XMLVALIDATE is unqualified
     or qualified with SYSFUN, the UDF version of
     DSN_XMLVALIDATE is invoked.
  
  The DSN_XMLVALIDATE function returns an XML value that is
  the result of applying XML schema validation to the first
  argument of the function. DSN_XMLVALIDATE can validate XML
  data up to a maximum length of 2 GB - 1 bytes, depending on
  system resources.
  
  >>-DSN_XMLVALIDATE(string-expression, ---------------------->>
  >>-+ schema-name-string----------------------------------+)-><
     '-target-namespace-uri-string,-schema-location-string-'
  
  The schema is SYSIBM.
  
  string-expression
   An expression that returns a built-in character, graphic,
   or binary string. The value must be a well-formed XML document
   that conforms to the XML Version 1.0 standard.
  
  schema-name-string
   An expression that returns a built-in varying length character
   string that is not a CLOB. The value specifies the name of
   the XML schema object that is used for validation. The value
   must not be an empty string or the null value, and the actual
   length must be less than or equal to 257. If the XML schema
   name is qualified, the qualifier must be SYSXSR (SYSXSR is
   the default qualifier). The value must identify a registered
   XML schema in the DB2 XML schema repository.
  
  target-namespace-uri-string
   An expression that returns a built-in varying length character
   string that is not a CLOB, with a length attribute that is
   not greater than 1000. The value specifies the target namespace
   name or universal resource identifier (URI) of the XML schema
   that is to be used for validation. If the value is an empty
   string of the null value, no namespace is used to locate the
   XML schema.
  
  schema-location-string
   An expression that returns a built-in varying length character
   string that is not a CLOB, with a length attribute that is
   not greater than 1000. The value specifies the XML schema
   location hint URI of the XML schema that is to be used for
   validation. If the value is an empty string of the null value,
   no schema location is used to locate the XML schema.
  
  If target-namespace-uri-string and schema-location-string are
  specified, the combination must identify a registered XML
  schema in the DB2 XML schema repository, and there must be
  only one such registered XML schema.
  
  A schema must be registered successfully in the DB2 XML schema
  repository before it can be used for DSN_XMLVALIDATE. If the
  validation fails, DB2 returns an error.
  
  To use the version of DSN_XMLVALIDATE described here, you need
  to explicitly qualify DSN_XMLVALIDATE with SYSIBM. When
  DSN_XMLVALIDATE is unqualified or is qualified with SYSFUN,
  the version of the DSN_XMLVALIDATE function that is used as
  input to the DSN_XMLPARSE function is invoked.
  
  The result of the function is an XML value. The result can be
  null; if the first argument is null, the result is the null
  value.
  
  Example 1: The following example shows how the DSN_XMLVALIDATE
  function validates the XML data that is contained in the
  value_host_var host variable. The XML schema,
  SYSXSR.ORDERSCHEMA, was registered prior to this statement:
   INSERT INTO T1(C1) VALUES(
   SYSIBM.DSN_XMLVALIDATE(:value_host_var, 'SYSXSR.MYXMLSCHEMA'));
  
  Example 2: The following example is similar to the previous
  example but references the namespace and schema location:
   INSERT INTO T1(C1) VALUES(
   SYSIBM.DSN_XMLVALIDATE(:value_host_var,
                          'http://www.n1.com',
                          'http://www.n1.com/report.xsd'));
  

Problem conclusion

• DB2 is modified to add a new SQL scalar function,
   SYSIBM.DSN_XMLVALIDATE using z/OS XMLSS
   which can validate up to a maximum length of 2G-1
   bytes, depending on system resources
   and at the same time take advantage of IBM
   Specialty Engines (zIIP or zAAP).
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK58408

Modules/Macros

• DSNXFN   DSNXOBFA DSNXOBFF DSNXOBF2 DSNXOBF3
  DSNXOBF4
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK58408

     UP10/07/15 P F007

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.