Configuring Db2 Direct

Configure Db2 Direct options or disable Db2 Direct.

1. To disable the Db2 Direct feature for a virtual table, in a VTB rule, set the variable OPTBDIDD to 1. For additional information, see the generic sample rule AVZMDTBL.
2. To define the VCATNAME for the Db2 system catalog tables, perform the following steps:
   1. Locate the Data Virtualization Manager configuration member. The server initialization member is shipped in data set member hlq.SAVZEXEC(AVZSIN00) and may have been copied to a new data set for customization.
   2. In the DEFINE DATABASE statement, use the SYSTEMVCAT parameter to define the VCATNAME for the system catalog tables, as shown in the following example:

       "DEFINE DATABASE TYPE(MEMBER)"                    ,
                      "NAME(DBA9)"                      ,
                      "LOCATION(RS28DDS9)"              ,
                      "DDFSTATUS(ENABLE)"               ,
                      "PORT(3725)"                      ,
                      "IPADDR(127.0.0.1)"                ,
                      "CCSID(37)"                       ,
                      "APPLNAME(DBA9DB2)"               ,
                      "SYSTEMVCAT(DDS9)"                ,
                      "IDLETIME(110)" 
      

3. To modify server parameters, perform the following steps:
   1. Locate the Data Virtualization Manager configuration member. The server initialization member is shipped in data set member hlq.SAVZEXEC(AVZSIN00) and may have been copied to a new data set for customization.
   2. Use the MODIFY PARM command to change a parameter value. For example, the following command disables Db2 Direct for the Data Virtualization Manager server:

      "MODIFY PARM NAME(DISABLEDB2DIRECT)    VALUE(YES)"

      The parameters in the following tables are available for use with Db2 Direct.

      Table 1. SQL parameters in group PRODSQL

      Parameter name	Parameter description	Default value
      DB2DIRECTSEGTBLPAGES	DB2-DIRECT SEGMENT TABLE PAGES Defines the number of 4K pages to be allocated for Db2 segment information. The default value is 8, which should be enough for most Db2 Direct queries. This parameter should only be changed if a query fails because the Db2 Direct segment table was exhausted.	8
      DISABLEDB2DIRECT	DISABLE DB2-DIRECT PROCESSING Disables Db2 Direct processing in the server.	NO
      DISABLEDB2DIRSEC	DISABLE DB2-DIRECT TABLE SECURITY Disables SQL table security checking when Db2 Direct is selected to process Db2 data. Disabling table security checking will allow access to Db2 data when the target Db2 subsystem is not active. Important: Unauthorized users who would normally receive a -551 SQLCODE attempting to access data through traditional APIs like DRDA may gain access to Db2 data.	NO

      Table 2. SQL parameters in group PRODTRACE

      Parameter name	Parameter description	Default value
      TRACEDB2DIRSTATS	TRACE DB2-DIRECT STATISTICS Enables tracing of a summary report to the system trace after each Db2 Direct query. Included in the trace are statistics about read and point operation in the Db2 linear data set(s) processed.	NO
      TRACEDB2DIROPEN	TRACE DB2-DIRECT OPEN CONTROL BLOCKS Enables tracing of control blocks created at the open of each linear data set for Db2 Direct processing.	NO
      TRACEDB2DIRSEGP	TRACE DB2-DIRECT SEGMENT PAGES Enables tracing if Db2 pages containing segmented map information.	NO
      TRACEDB2DIRDICTP	TRACE DB2-DIRECT DICTIONARY PAGES Enables tracing of the compression dictionary used to compress and expand rows stored in Db2 linear data sets.	NO
      TRACEDB2DIRDATAP	TRACE DB2-DIRECT DATA PAGES Enables tracing of data pages in a linear data set containing Db2 rows.	NO
      TRACEDB2DIRROWS	TRACE DB2-DIRECT ROWS Enables tracing of rows extracted from data pages in a Db2 linear data set. If rows are compressed, an additional trace is created of the uncompressed row data.	NO