Inaccurate query results for Db2 z/OS remote data sources (Data Virtualization)

Resolving the problem

To solve this issue, run the following commands to set the required Db2 registry variable. A platform administrator must run these commands from the c-dv2u-cv-db2u-0 pod. After entering the container, the administrator must change to the db2inst1 user by using the command su - db2inst1.

These commands will first get the current setting of the DB2_DV_OVERRIDES variable, then add the NO_SSPD(DB2) setting to the variable, and then ensure SQL statements are flushed from the package cache.

1. Obtain the current settings of the DB2_DV_OVERRIDES variable.

   db2set | grep DB2_DV_OVERRIDES

   For example the output of the previous command might be:

   DB2_DV_OVERRIDES=EN_OJMQT,EN_JOINFILTER,EN_GAIANQUERY_JOINFILTER

2. Using the value from step 1, update the variable setting. The new value for the variable is formed by taking the prior value and appending `,NO_SSPD(DB2)`.With the above example the new value would be:

   `EN_OJMQT,EN_JOINFILTER,EN_GAIANQUERY_JOINFILTER,NO_SSPD(DB2)`

3. In the following command, use the value determined in step 2 to provide new_variable_value.

   db2set | grep DB2_DV_OVERRIDES; 
   db2set -im DB2_DV_OVERRIDES="new_variable_value";
   db2 flush package cache dynamic; 

   • To update the variable only for the a single query, append the following directive to the query text.

     /*<OPTGUIDELINES><REGISTRY> <OPTION NAME='DB2_DV_OVERRIDES' VALUE='new variable value'/></REGISTRY></OPTGUIDELINES>*/

     For more information, see Optimization profiles and guidelines

   • To update the variable globally, use the following method.

     db2set -im DB2_DV_OVERRIDES="new variable value";db2 flush package cache dynamic;