Welcome
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
These topics provide the information required to administer HCL Informix®.
Disk, memory, and process management
Manage disk space
You can use several utilities and tools to manage disk spaces and the data that the database server controls.
Drop a chunk
Use the onspaces utility to drop a chunk from a dbspace.

HCL Informix® V15.0.0 documentation
Welcome to the documentation for HCL Informix® 15.0.0 and related client tools and products.
Product overview
HCL Informix® is a fast and scalable database server that manages traditional relational, object-relational, and dimensional databases. Its small footprint and self-managing capabilities are suited to embedded data-management solutions.
Installing
These topics describe how to install HCL Informix® database servers, client products, and DataBlade® modules.
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
    These topics provide 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.
      - Manage disk space
        You can use several utilities and tools to manage disk spaces and the data that the database server controls.
        Allocate disk space
        This section explains how to allocate disk space for the database server.
        Specify names for storage spaces and chunks
        Chunk names follow the same rules as storage-space names.
        Monitor storage spaces
        You can monitor the status of storage spaces and configure how you are notified when a storage space becomes full.
        Manage dbspaces
        This section contains information about creating standard and temporary dbspaces with and without the default page size, specifying the first and next extent sizes for the tblspace tblspace in a dbspace when you create the dbspace, and adding a chunk to a dbspace or blobspace.
        Manage blobspaces
        This section explains how to create a blobspace and determine the blobpage size.
        Manage sbspaces
        This section describes how to create a standard or temporary sbspace, monitor the metadata and user-data areas, add a chunk to an sbspace, and alter storage characteristics of smart large objects.
        Manage the plogspace
        You create or move the plogspace with the onspaces utility or equivalent SQL administration API command.
        Automatic space management
        You can configure the server to add more storage space automatically when more space is required. You use space more effectively and ensure that space is allocated as necessary, while reducing out-of-space errors. You reduce the time required to manually monitor your spaces to determine which storage space might run out of free space. If you configure the server to automatically add space, you can also manually expand a space or extend a chunk.
        Drop a chunk
        Use the onspaces utility to drop a chunk from a dbspace.
        Verify whether a chunk is empty
        Drop a chunk from a dbspace with onspaces
        Drop a chunk from a blobspace
        Drop a chunk from an sbspace with onspaces
        Drop a storage space
        Use onspaces or ON-Monitor to drop a dbspace, temporary dbspace, blobspace, sbspace, temporary sbspace, or extspace.
        Creating a space or chunk from the storage pool
        If your storage pool contains entries, you can create storage spaces or chunks from free space in the storage pool.
        Returning empty space to the storage pool
        You can return the space from an empty chunk or storage space to the storage pool.
        Manage extspaces
        Skip inaccessible fragments
        Display databases
        You can display the databases that you create with SMI tables or ON-Monitor.
        Monitor disk usage
        Multitenancy
        You can segregate data, storage space, and processing resources for multiple client organizations by creating multiple tenant databases in a single instance of Informix®.
        Storage optimization
        Data compression and consolidation processes can minimize the disk space that is used by your data and indexes.Data compression and consolidation processes can minimize the disk space that is used by your data.
        Load data into a table
      - 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.
    - HCL Informix® server licensing
  - Administrator's Reference
    These topics include 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
    This publication describes how to use the DB-Access utility to access, modify, and retrieve information from HCL® Informix® database servers.
  - High-Performance Loader User's Guide
    These topics describe how to use the HCL Informix® High-Performance Loader (HPL) to load and unload large quantities of data efficiently to or from Informix databases.
  - Performance Guide
    These topics describe 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
    These topics describe 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
  These topics describe how to use the HCL® 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
  These topics describe the concepts of data replication using HCL Informix® Enterprise Replication, including how to design your replication system, as well as administer and manage data replication throughout your enterprise.
Migrating and upgrading
You can upgrade to the 15.0.0 release of HCL Informix® or migrate from other database servers to Informix. Upgrading is an in-place migration method that uses your existing hardware and operating system software. Some changes to the Informix database server can affect upgrading from a previous release. The resources that are external to the information center are marked as such.
Client APIs and tools
You can use the HCL Informix® implementation of client APIs to develop applications for Informix database servers.
Embedding Informix®
When you embed HCL Informix®, you can use enterprise-class high-availability and high performance with embeddability features such as easy programmability, a small disk and memory footprint, and silent deployment.
Extending Informix®
Beyond standard relational database objects, HCL Informix® can be extended to handle specialized data types, access methods, routines, and other objects. Informix includes many built-in extensions that are fully integrated in the database server. Informix also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for Informix.
Data warehousing
In addition to designing and implementing Informix® dimensional databases, you can use tools to create data warehouse applications and optimize your data warehouse queries.
Designing databases
The first step in creating a relational database is to construct a data model, which is a precise, complete definition of the data you want to store. After you prepare your data model, you must implement it as a database and tables. To implement your data model, you first select a data type for each column and then you create a database and tables and populate the tables with data. You can also implement fragmentation strategies and control access to your data.
JSON compatibility
You can use the popular JSON-oriented query language created by MongoDB to interact with data stored in HCL Informix®.
Security
You can secure your Informix® database server and the data that is stored in your Informix databases. You can encrypt data, secure connections, control user privileges and access, and audit data security.
SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
Troubleshooting HCL Informix®
Several troubleshooting techniques, tools, and resources are available for resolving problems that you encounter in your HCL Informix® database server environment.
Informix PDF guides

Drop a chunk

Use the onspaces utility to drop a chunk from a dbspace.

Before you drop a chunk, ensure that the database server is in the correct mode, using the following table as a guideline.

Table 1. Database server modes for dropping chunks
Chunk type	Database server in online mode	Database server in administration or quiescent mode	Database server in offline mode
Dbspace chunk	Yes	Yes	No
Temporary dbspace chunk	Yes	Yes	No
Blobspace chunk	No	Yes	No
Sbspace or temporary sbspace chunk	Yes	Yes	No