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Administering
In addition to administering the database server, you can tune performance, replicate data, and archive data.
Enterprise Replication
The HCL® Informix® Enterprise Replication Guide describes the concepts of data replication using Informix Enterprise Replication, including how to design your replication system, as well as administer and manage data replication throughout your enterprise.
Setting up and managing Enterprise Replication
After you design your replication system, you define it and start replication.
Preparing the Replication Environment
The following topics explain the steps that are required for setting up Enterprise Replication.
Preparing the Disk
These topics describe how to prepare your disk for Enterprise Replication.
Setting Up Send and Receive Queue Spool Areas
Row Data sbspaces
Replicated data might include UDT and CLOB or BLOB data types. Therefore, the spooled row data is stored as smart large objects in one or more sbspaces.
Logging Mode for sbspaces

Administering
In addition to administering the database server, you can tune performance, replicate data, and archive data.
- System administration
  These topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL Informix® database servers.
- Backup and Restore Guide
  The Informix® Backup and Restore Guide describes how to use the Informix ON-Bar and ontape utilities to back up and restore database server data. These utilities enable you to recover your databases after data is lost or becomes corrupted due to hardware or software failure or accident.
- Enterprise Replication
  The HCL® Informix® Enterprise Replication Guide describes the concepts of data replication using Informix Enterprise Replication, including how to design your replication system, as well as administer and manage data replication throughout your enterprise.
  - About Enterprise Replication
    Informix® Enterprise Replication generates and manages multiple copies of data at one or more sites, which allows an enterprise to share corporate data throughout its organization.
  - Planning and designing for Enterprise Replication
    Before you set up your replication system, plan how to include Enterprise Replication into your database server environment, design your database schema by following Enterprise Replication requirements, and then design your replication system between database servers.
  - Setting up and managing Enterprise Replication
    After you design your replication system, you define it and start replication.
    - Preparing the Replication Environment
      The following topics explain the steps that are required for setting up Enterprise Replication.
      - Preparing the Network Environment
        You must prepare the network environment for each database server in an Enterprise Replication domain.
      - Preparing the Disk
        These topics describe how to prepare your disk for Enterprise Replication.
        Logical Log Configuration Disk Space
        Logical Log Configuration Guidelines
        Logical logs must be configured correctly for Enterprise Replication.
        Disk Space for Delete Tables
        If you use the time stamp, time stamp and SPL routine, or delete wins conflict resolution rules, you must provide enough disk space for the delete tables that Enterprise Replication creates to keep track of modified rows for conflict resolution.
        Shadow column disk space
        If you plan to use shadow columns, make sure to allow additional disk space for their values.
        Setting Up Send and Receive Queue Spool Areas
        Row Data sbspaces
        Replicated data might include UDT and CLOB or BLOB data types. Therefore, the spooled row data is stored as smart large objects in one or more sbspaces.
        Creating sbspaces for Spooled Row Data
        You must create dedicated sbspaces for spooled row data.
        Logging Mode for sbspaces
        Dropping a Spooled Row Data sbspace
        Setting Up the Grouper Paging File
        Creating ATS and RIS Directories
        You can create directories for Aborted Transactions Spooling (ATS) and Row Information Spooling (RIS) files instead of using the default directories.
      - Preparing the Database Server Environment
        To prepare the database server environment, set database server environment variables and configuration parameters, and synchronize the operating system time on all participating database servers.
      - Preparing Data for Replication
      - Load and unload data
        You can load data into or unload data out of tables in your replication environment in various ways, depending on your circumstances.
      - Data Preparation Example
    - Using High-Availability Clusters with Enterprise Replication
    - Defining Replication Servers, Replicates, Participants, and Replicate Sets
      These topics describe the steps defining and starting Enterprise Replication.
    - Grid setup and management
      A grid is a set of replication servers that are configured to simplify administration. When you run SQL data definition statements from within a grid context on a grid server, the statements propagate to all servers in the grid. You can run SQL data manipulation statements and routines through grid routines. You can choose to set up replication automatically when you create a table through a grid. You can propagate external files to other servers in the grid.
    - Shard cluster setup
      Sharding is a way to horizontally partition a single table across multiple database servers in a shard cluster. Enterprise Replication moves the data from the source server to the appropriate target server as specified by the sharding method. You query a sharded table as if the entire table is on the local server. You do not need to know where the data is. Queries that are performed on one shard server retrieve the relevant data from other servers in a shard cluster. Sharding reduces the index size on each shard server and distributes performance across hardware. You can add shard servers to the shard cluster as your data grows.
    - Managing Replication Servers and Replicates
    - Monitor and troubleshooting Enterprise Replication
      You can monitor and diagnose problems with the Enterprise Replication system by using several different methods, depending on your needs.
  - Push data feature
  - Loopback replication
  - Appendixes

Logging Mode for sbspaces

About this task

Enterprise Replication uses the default log mode that the sbspace was created with for spooling row data.

Create sbspaces with a default logging mode of ON or OFF according to the types of transactions Enterprise Replication replicates:

LOGGING=ON
Create sbspaces with LOGGING set to ON to support these situations:
- Replicated systems with high-availability clusters
  Enterprise Replication must use logging sbspaces for transactions involved in high-availability clusters.
- Small transactions
  Enterprise Replication uses logging sbspaces for transactions that are less than a page size (2K or 4K) of replicated data.
For logging sbspaces, performance might be enhanced because logging mode enables asynchronous IO. However, a logging sbspace consumes additional logical-log space.
LOGGING=OFF
Create sbspaces with LOGGING set to OFF to support replication of large transactions (greater than a page size of replicated data).
It is recommended that you mirror non-logging sbspaces. For more information, see the chapter on managing disk space in the Informix® Administrator's Guide and the Informix® Administrator's Reference.

For non-logging sbspaces, performance is enhanced on the database server when Enterprise Replication spools to disk because Enterprise Replication writes less data to disk.

Important: Do not change the Enterprise Replication sbspace default log mode while Enterprise Replication is running. To change the default log mode, follow the procedure below.

You can change the default logging mode of the row data sbspace if you have more than one sbspace specified by the CDR_QDATA_SBSPACE configuration parameter.

To change the default logging mode of a row data sbspace:

Procedure

Shut down the database server.
Remove the sbspace from the CDR_QDATA_SBSPACE configuration parameter value list.
Start the database server in recovery mode.
Wait for all the smart large objects to get deleted from the sbspace. Use the onstat -g smb lod command to check for smart large objects stored in an sbspace.
Change the default logging mode for the sbspace.
Add the sbspace name to the CDR_QDATA_SBSPACE configuration parameter value list.
Shut down and restart the database server using the onmode -ky and oninit commands.