CHAPTER 3: Configuration Parameters



3.1 Introduction

The Empress Connectivity (ODBC) Server can be started with the command: 

  $EMPRESSPATH/bin/empsvadm odbc_server_name start -f odbc_server_configuration_file
This starts an Empress Connectivity (ODBC) Server. The server uses the following configuration files: Successful start of an Empress Connectivity (ODBC) Server gives a "success message": 

  server 'empodbcsv' : start request ok

Information about the status of the started server will also be shown. A sample is given in: [Sample Connectivity (ODBC) Server status information]



3.2 Network Configuration Files

 The Empress Server Network Configurations are defined in Network Configuration Files. These are:
  1. Network Type Configuration File, with the default in EMPRESSPATH/config/nettype.cfg
  2. Network Server Configuration File, with the default in $EMPRESSPATH/config/netserver.cfg
Refer to Network Configuration for detailed information about these files.



3.3 Empress Connectivity (ODBC) Server Configuration File

The Empress Connectivity (ODBC) Server Configuration File is used to define the Empress ODBC connection information for each database. This is an option while starting Empress Connectivity (ODBC) Server. If this file is not specified, the Connectivity (ODBC) Server will use the default values. Here is an example: 

          # GLOBAL SECTION.

          PRE_CHECK_DB = X                  

          PRE_OPEN_DB = X

          TRACEFILE=/tmp/global.out        

          TRACELEVEL=1

          QUERY_TIMEOUT = 300

          MAX_ROWS = 0                     



          # LOCAL SECTION.

          MSODBCDB

             NAME=testdb

             LOCATION=/home/foo/testdb

             PRE_OPEN_DB =                  

             PRE_CHECK_DB =

             PRE_OPEN_TABLE = table1

             PRE_OPEN_TABLE = table2

             QUERY_TIMEOUT = 3600

             MAX_ROWS = 10

          MSODBCDBEND



          MSODBCDB

             NAME=testdb2

             LOCATION=/home/foo/testdb2

             PRE_OPEN_DB =

             PRE_CHECK_DB =

             PRE_OPEN_TABLE = table3

             PRE_OPEN_TABLE = table4

             QUERY_TIMEOUT = 40

             MAX_ROWS = 3600

          MSODBCDBEND

This file contains only one "global section" which defines the Empress ODBC connection attributes for all the databases. This file contains multiple "local section" which defines the Empress ODBC connection attributes for a specific database. Each "local section" starts from MSODBCDB and ends with MSODBCDBEND . The settings in the "local section" overwrite the settings in the "global section" for the specific database defined by the NAME attribute in the "local section".

TheEmpress Connectivity (ODBC) Server Configuration File uses the following format to set an entry

   configuration_attribute = value

To unset an entry, just leave it as:

   configuration_attribute =

In this file all spaces and tabs are ignored.

The followings are valid configuration_attribute:

PRE_CHECK_DB = x 

If PRE_CHECK_DB is set, the Empress Connectivity (ODBC) Server will check to see if the database defined in the LOCAL SECTION is a valid database. If the database is  not valid,  the Empress Connectivity (ODBC) Server will fail and give out an error message.  

 
PRE_OPEN_DB = x

If  PRE_OPEN_DB is set, the Empress Connectivity (ODBC) Server will pre-open the tables in the database. This can improve the performance of  the Empress ODBC Connection.  Pre-open tables are defined in the "local section".

 
TRACEFILE = full_path_filename

If TRACEFILEis set, the Empress Connectivity (ODBC) Server will generate an ODBC trace log file for debugging purposes.
This option should only be set when debugging. 

 
TRACELEVEL = trace_level_value

TRACELEVEL can be set to a number from 0 to 3. "0" means no tracing. The more detailed information will be generated if a larger number is set.

 
QUERY_TIMEOUT = query_timeout_value

A QUERY_TIMEOUT setting corresponds to the number of seconds an ODBC client application waits for an SQL statement to execute, before returning to the application.

MAX_ROW = max_row_value

A MAX_ROW setting corresponds to the maximum number of rows (i.e. records) which is returned to the ODBC client application for a SELECT statement. "0" means all results.

 
NAME = database_name

NAME defines the logical database name. 

 
LOCATION=physical_db_location

LOCATION specifies the physical location of database. If it is not set, the database specified in NAME will be treated as physical directory name.

 
PRE_OPEN_TABLE = table_name

PRE_OPEN_TABLE is used to set the pre-opened table name. Each database could have multiple PRE_OPEN_TABLE settings.

 

3.4 Empress Server Password File

Empress Server Password File is used to define the login name and password for Empress Connectivity (ODBC) Server. It also defines the access control list for each login. Please refer to Password File Utility for more detailed information.