code: private void checkDataSourceRef() {
  
          Object configuredDSR = _props.get("dataSourceRef");
          if (configuredDSR == null) {
              if (tc.isDebugEnabled())
                  Tr.debug(tc, "dataSourceRef is not specified, log to filesys");
              _isSQLRecoveryLog = false;
          } else {
              if (tc.isDebugEnabled())
                  Tr.debug(tc, "dataSourceRef is specified, log to RDBMS");
              // We'll set the logDir to maintain tWAS code compatibility. First we need to
              // check get the table suffix string if it is set in server.xml
              String suffixStr = (String) _props.get("transactionLogDBTableSuffix");
  
              if (tc.isDebugEnabled())
                  Tr.debug(tc, "suffixStr is " + suffixStr + ", of length " + suffixStr.length());
  
              if (suffixStr != null && !suffixStr.trim().isEmpty()) {
                  suffixStr = suffixStr.trim();
                  logDir = "custom://com.ibm.rls.jdbc.SQLRecoveryLogFactory?datasource=Liberty" +
                           ",tablesuffix=" + suffixStr;
              } else
                  logDir = "custom://com.ibm.rls.jdbc.SQLRecoveryLogFactory?datasource=Liberty";
  
              if (tc.isDebugEnabled())
                  Tr.debug(tc, "logDir now set to ", logDir);
              _isSQLRecoveryLog = true;
          }
      }
docs: Determine whether the server is configured to store Tran Logs in an RDBMS,