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 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.
Appendixes
Messages in the database server log
Unnumbered messages are printed in the database server message log (online.log). The error messages include corrective actions.
Conversion and reversion error messages
If conversion or reversion is not successful, error messages are stored in the online.log file to help you identify what failed and what actions to take to fix the problem.
Cannot revert constraint with id id (in syschecks).

HCL Informix® V15.0 documentation
Welcome to the documentation for HCL Informix® 15.0 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®.
  - 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.
    - Configuring and monitoring Informix®
    - Administrative Utilities
    - SQL Administration API
    - Appendixes
      - Database server files
        Database server files are created in default directories, or in a directory that the relevant configuration parameter specifies. A database administrator might need to edit or examine the content of files that are used by the database server.
      - Troubleshooting errors
        Occasionally, a series of events causes the database server to return unexpected error codes.
      - Event Alarms
        The database server provides a mechanism for automatically triggering administrative actions based on an event that occurs in the database server environment. This mechanism is the event-alarm feature.
      - Messages in the database server log
        Unnumbered messages are printed in the database server message log (online.log). The error messages include corrective actions.
        How the Messages Are Ordered in This Chapter
        Messages: A-B
        Messages: C
        Messages: D-E-F
        Messages: G-H-I
        Messages: J-K-L-M
        Messages: N-O-P
        Messages: Q-R-S
        Messages: T-U-V
        Messages: W-X-Y-Z
        Messages: Symbols
        Conversion and reversion error messages
        If conversion or reversion is not successful, error messages are stored in the online.log file to help you identify what failed and what actions to take to fix the problem.
        Cannot revert constraint with id id (in syschecks).
        Cannot revert new fragment expression for index index, tabid id.
        Cannot revert new table fragment expression for table with id id.
        Conversion of pre 7.3 in-place alter started status.
        Conversion of pre 9.2 database tblspaces status.
        The conversion of the database name has failed.
        Database name is not revertible...
        Database name: Must drop trigger (id = id_number) before attempting reversion.
        The dummy updates failed while converting database name. This may imply data corruption in the database. If so, restore the original database with the tape backup. For more information, see output_file.
        Error in slow altering a system table.
        External conversion aborted due to incompatible sysmaster database.
        Internal server error.
        Must drop long identifiers in table name in database name
        Must drop new database (name) before attempting reversion. Iserrno error_number
        Must drop new user defined statistics in database name, iserrno number
        'onpload' conversion failed. For details, look in $INFORMIXDIR/etc/conpload.out.
        ...'onpload' reversion failed. For details, look in $INFORMIXDIR/etc/revpload.out.
        The pload database contains load/unload jobs referring to long table names, column names, or database names. These jobs will not work as expected until they are redefined.
        Reversion canceled.
        There is a semi-detached index in this table, which cannot be reverted.
        WARNING: Target server version must have a certified Storage Manager installed after conversion/reversion and before bringing up server.
        Dynamic Log Messages
        Sbspace Metadata Messages
        Truncate Table Messages
      - Limits in Informix®
        This topic lists the system-level and table-level parameter limits, the system defaults, and the access capabilities of Informix®.
  - 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 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.
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.

Cannot revert constraint with id `id` (in syschecks).

Cause

The database has a constraint that was defined in a version more recent than the one to which you are reverting.

Action

Drop the specified constraint and retry reversion.

Cannot revert constraint with id id (in syschecks).

Cause

Action

Cannot revert constraint with id `id` (in syschecks).