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SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
Guide to SQL: Syntax
Other syntax segments
These topics describe syntax segments, which are language elements, such as database object names or optimizer directives, that appear as a subdiagram reference in the syntax diagrams of some SQL or SPL statements.
Routine modifier
A routine modifier specifies characteristics of how a user-defined routine (UDR) behaves.
Adding or Modifying a Routine Modifier
Use this segment in the ALTER FUNCTION, ALTER PROCEDURE, or ALTER ROUTINE statement to add or modify values for routine modifiers of a UDR.

SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
- Guide to SQL: Syntax
  - Overview of SQL syntax
    These topics provide an overview about how to use the SQL statements, SPL statements, and syntax segments.
  - SQL statements
    This chapter describes the syntax and semantics of SQL statements that are recognized by Informix®.
  - SPL statements
    These topics describe Stored Procedure Language (SPL) statements, which you use to write SPL routines. You can store these routines in the database as user-defined routines (UDRs).
  - Data types and expressions
    These topics describe the data types and expressions that Informix®supports.
  - Other syntax segments
    These topics describe syntax segments, which are language elements, such as database object names or optimizer directives, that appear as a subdiagram reference in the syntax diagrams of some SQL or SPL statements.
    - Arguments
    - Collection-Derived Table
      A collection-derived table is a virtual table in which the values in the rows of the table are equivalent to elements of a collection. Use this segment where you see a reference to Collection-Derived Table in a syntax diagram. This syntax is an extension to the ANSI/ISO standard for SQL.
    - Database Name
    - Database Object Name
    - External Routine Reference
      Include the External Routine Reference clause when you write an external routine. This option is not available for SPL routines.
    - Identifier
      An identifier specifies the unqualified name of a database object, such as an access method, aggregate, alias, blobspace, cast, column, constraint, correlation, data type, index, operator class, partition, procedure, table, trigger, sequence, synonym, or view. Use the Identifier segment whenever you see a reference to an identifier in a syntax diagram.
    - Jar Name
      Use the Jar Name segment to specify the name of a jar ID. Use this segment whenever you see a reference to Jar Name in a syntax diagram.
    - Optimizer Directives
      The Optimizer Directives segment specifies keywords that you can use to partially or fully specify the query plan of the optimizer. Use this segment whenever you see a reference to Optimizer Directives in a syntax diagram.
    - Owner name
      The owner name specifies the owner of a database object. Use this segment whenever you see a reference to Owner Name in a syntax diagram.
    - Purpose Options
    - Return Clause
    - Routine modifier
      A routine modifier specifies characteristics of how a user-defined routine (UDR) behaves.
      - Adding or Modifying a Routine Modifier
        Use this segment in the ALTER FUNCTION, ALTER PROCEDURE, or ALTER ROUTINE statement to add or modify values for routine modifiers of a UDR.
      - Modifier Descriptions
    - Routine Parameter List
    - Shared-Object Filename
      Use a shared-object filename to specify a pathname to an executable object file when you register or alter an external routine.
    - Specific Name
    - Statement Block
  - Built-In Routines
  - Appendixes
- Guide to SQL: Reference
  The Informix® Guide to SQL: Reference contains the reference information for the system catalog tables, data types, and environment variables of the HCL Informix dialect of the SQL language, as implemented in HCL Informix. These topics also include information about the stores_demo, sales_demo, and superstore_demo databases that are included with HCL Informix.
- Guide to SQL: Tutorial
  The Informix® Guide to SQL: Tutorial shows how to use basic and advanced structured query language (SQL) to access and manipulate the data in your databases. It discusses the data manipulation language (DML) statements as well as triggers and stored procedure language (SPL) routines, which DML statements often use.

Adding or Modifying a Routine Modifier

Use this segment in the ALTER FUNCTION, ALTER PROCEDURE, or ALTER ROUTINE statement to add or modify values for routine modifiers of a UDR.

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Adding or Modifying a Routine Modifier

{ { { ^[]^[] | [ [ NOT ] VARIANT ] } | NEGATOR = neg_func } | { ^[] | CLASS = class_name | ITERATOR | PARALLELIZABLE | ^[] { { HANDLESNULLS } | INTERNAL | { PERCALL_COST = { cost | 0 } | COSTFUNC = cost_func } | { SELFUNC = sel_func | SELCONST = selectivity } | STACK = stack_size } } }


Element	Description	Restrictions	Syntax
`class_name`	Virtual processor (VP) class in which to run the external routine	Any C UDR must run in the CPU VP or in a user-defined VP class	Quoted String.
`cost`	CPU use cost for each invocation of a C-language UDR. Default is `0`.	Integer; 1 `cost` 2³¹-1 (highest cost).	Literal Number
`cost_func`	Name of a companion user-defined cost function to run	Must have same owner as the UDR. Execute privilege is needed to run.	Identifier
`neg_func`	Negator function that can be invoked instead of the UDR	Must have same owner as the UDR. Execute privilege is needed to run.	Identifier
`sel_func`	Name of a companion user-defined selectivity function to invoke	Must have same owner as the UDR. Execute privilege is needed to run.	Identifier
`selectivity`	CPU use cost for each invocation of a C-language UDR. Default is `0.`	See Concept of Selectivity.	Literal Number
`stack_size`	Size (in bytes) of stack of the thread that runs the C-language UDR	Must be a positive integer	Literal Number

You can add these modifiers in any order. If you list the same modifier more than once, the last setting overrides any previous values.

¹ C language

² Stored Procedure Language

³ External routines only