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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.
Administrator's Guide
The Informix® Administrator's Guide provides the information required to administer HCL Informix.
Disk, memory, and process management
Data storage
The database server uses physical units of storage to allocate disk space. It stores data in logical units. Unlike the logical units of storage whose size fluctuates, each of the physical units has a fixed or assigned size that is determined by the disk architecture.
Dbspaces
A dbspace is a logical unit that can contain between 1 and 32,766 chunks. The database server uses the dbspace to store databases and tables. Place databases, tables, logical-log files, and the physical log in dbspaces.
Root dbspace
The root dbspace is the initial dbspace that the database server creates.

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.
  - List of utilities
    HCL Informix® includes utilities and applications that you can use to perform administrative tasks and capture information about configuration and performance.
  - Administrator's Guide
    The Informix® Administrator's Guide provides the information required to administer HCL Informix.
    - The database server
    - Disk, memory, and process management
      - Virtual processors and threads
        These topics describe virtual processors, explain how threads run within the virtual processors, and explain how the database server uses virtual processors and threads to improve performance.
      - Manage virtual processors
        These topics describe how to set the configuration parameters that affect database server virtual processors, and how to start and stop virtual processors.
      - Shared memory
        These topics describe the content of database server shared memory, the factors that determine the sizes of shared-memory areas, and how data moves into and out of shared memory.
      - Manage shared memory
      - Data storage
        The database server uses physical units of storage to allocate disk space. It stores data in logical units. Unlike the logical units of storage whose size fluctuates, each of the physical units has a fixed or assigned size that is determined by the disk architecture.
        Chunks
        A chunk is the largest unit of physical disk dedicated to database server data storage.
        Pages
        A page is the physical unit of disk storage that the database server uses to read from and write to Informix® databases.
        Blobpages
        A blobpage is the unit of disk-space allocation that the database server uses to store simple large objects (TEXT or BYTE data) within a blobspace.
        Sbpages
        An sbpage is the type of page that the database server uses to store smart large objects within an sbspace. Unlike blobpages, sbpages are not configurable. An sbpage is the same size as the database server page, which is usually 2 KB on UNIX™ and 4 KB on Windows™.
        Extents
        An extent consists of a collection of contiguous pages that store data for a given table.
        Dbspaces
        A dbspace is a logical unit that can contain between 1 and 32,766 chunks. The database server uses the dbspace to store databases and tables. Place databases, tables, logical-log files, and the physical log in dbspaces.
        Control of where simple large object data is stored
        A key responsibility of the database server administrator is to control where the database server stores data.
        Root dbspace
        The root dbspace is the initial dbspace that the database server creates.
        Temporary dbspaces
        A temporary dbspace is a dbspace reserved exclusively for the storage of temporary tables. It behaves differently from a standard dbspace in many ways.
        Blobspaces
        A blobspace is a logical storage unit composed of one or more chunks that store only TEXT and BYTE data.
        Sbspaces
        An sbspace is a logical storage unit composed of one or more chunks that store smart large objects.
        Plogspace
        A plogspace is a logical storage unit that is composed of one chunk that stores the physical log. When the physical log is in the plogspace, the database server increases the size of the physical log as needed to improve performance.
        Extspaces
        An extspace is a logical name associated with an arbitrary string that signifies the location of external data. The resource that the extspace references depends on a user-defined access method for accessing its contents.
        Databases
        A database is a logical storage unit that contains tables and indexes. Each database also contains a system catalog that tracks information about many of the elements in the database, including tables, indexes, SPL routines, and integrity constraints.
        Tables
        In relational database systems, a table is a row of column headings together with zero or more rows of data values. The row of column headings identifies one or more columns and a data type for each column.
        Table types for Informix®
        You can create logging or nonlogging tables in a logging database on HCL Informix®. The two table types are STANDARD (logging tables) and RAW (nonlogging tables). The default standard table is like a table created in earlier versions without a special keyword specified. You can create either a STANDARD or RAW table and change tables from one type to another.
        Tblspaces
        Database server administrators sometimes must track disk use by a particular table. A tblspace contains all the disk space allocated to a given table or table fragment (if the table is fragmented). A separate tblspace contains the disk space allocated for the associated index.
        Table fragmentation and data storage
        The fragmentation feature gives you more control over where the database stores data. You are not limited to specifying the locations of individual tables and indexes. You can also specify the location of table and index fragments, which are different parts of a table or index that are on different storage spaces.
        Amount of disk space needed to store data
        To determine how much disk space you require, follow these steps:
        The storage pool
        Every instance of the database server has a storage pool. The storage pool contains information about the directories, cooked files, and raw devices that the server can use if necessary to automatically expand an existing dbspace, temporary dbspace, sbspace, temporary sbspace, or blobspace.
        Disk-layout guidelines
        The following goals are typical for efficient disk layout:
        Sample disk layouts
        When setting out to organize disk space, the database server administrator usually has one or more of the following objectives in mind:
        Logical-volume manager
        You can use the logical-volume manager (LVM) utility to manage your disk space through user-defined logical volumes.
      - Manage disk space
        You can use several utilities and tools to manage disk spaces and the data that the database server controls.
      - Moving data with external tables
        You can use external tables to load and unload database data.
      - Storage space encryption
        You can encrypt storage spaces (dbspaces, blobspaces and smart blobspaces) with Informix Dynamic Server. The data in encrypted storage spaces is unintelligible without the encryption key. Encrypting storage spaces is an effective way to protect sensitive information that is stored on disk.
    - Logging and log administration
    - Fault tolerance
    - High availability and scalability
      A successful production environment requires database systems that are always available, with minimal if any planned outages, and that can be scaled quickly and easily as business requirements change.
    - Distributed data
    - Overview of automatic monitoring and corrective actions
      You can use the SQL administration API, the Scheduler, and drill-down queries to manage automatic maintenance, monitoring, and administrative tasks.
  - Administrator's Reference
    The Informix® Administrator's Reference includes comprehensive descriptions of HCL Informix configuration parameters, the system-monitoring interface (SMI) tables in the sysmaster database, the syntax of database server utilities such as onmode and onstat, logical-log records, disk structures, event alarms, and unnumbered error messages.
  - DB-Access User's Guide
    The Informix® DB-Access User's Guide describes how to use the DB-Access utility to access, modify, and retrieve information from Informix database servers.
  - High-Performance Loader User's Guide
    The describes how to use the HCL Informix® to load and unload large quantities of data efficiently to or from Informix databases.
  - Performance Guide
    The Informix® Performance Guide describes how to configure and operate your HCL Informix database server to improve overall system throughput and to improve the performance of SQL queries.
  - SNMP Subagent Guide
    The describes the Simple Network Management Protocol (SNMP) and the software that you need to use SNMP to monitor and manage HCL Informix® database servers and databases.
  - InformixHQ Guide
    InformixHQ is a modern web console for visualizing, monitoring, and managing your Informix server instances. It is purpose built for ease-of-use, scaling out, and optimizing DevOps needs. It provides critical performance management capabilities, monitoring how key performance metrics are changing over time and tracking how efficiently Informix is running your workload even when you’ve stepped away from your screen. Its monitoring system feeds directly into a customizable alerting system so you can be immediately alerted via email, Twilio, or PagerDuty whenever an issue occurs on one of your Informix database server instances. InformixHQ is designed to be scalable to efficiently manage and monitor as many Informix database server instances as you need. Moreover, it's a tool that can be shared by the DBAs, the app developers, the ops engineers, and management and accessed from any desktop, laptop, or mobile device. InformixHQ is the centralized hub for graphical monitoring, alerting, and administration of your 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.

Root dbspace

The root dbspace is the initial dbspace that the database server creates.

The root dbspace is special because it contains reserved pages and internal tables that describe and track all physical and logical units of storage. (For more information about these topics, see Tables and the disk structures and storage chapter in the Informix® Administrator's Reference.) The initial chunk of the root dbspace and its mirror are the only chunks created during disk-space setup. You can add other chunks to the root dbspace after disk-space setup.

The following disk-configuration parameters in the onconfig configuration file refer to the first (initial) chunk of the root dbspace:

ROOTPATH
ROOTOFFSET
ROOTNAME
MIRRORPATH
MIRROROFFSET
TBLTBLFIRST
TBLTBLNEXT

The root dbspace is also the default dbspace location for any database created with the CREATE DATABASE statement.

The root dbspace is the default location for all temporary tables created by the database server to perform requested data management.

See Size of the root dbspace for information about how much space to allocate for the root dbspace. You can also add extra chunks to the root dbspace after you set up database server disk space.