Overview

Omnidex supports the most common RDBMS data types, as well as some Omnidex proprietary data types for internal use and for flat file databases. These data types are used in the column definitions in the OMNIDEX environment catalog and govern how the data will be indexes and returned to an application. The data types declared in the OMNIDEX environment catalog do not affect the data type definitions in the underlying database.

Textual and binary data types are declared with a length parameter, indicating the maximum size of the data in that column. The length is passed as a parameter of the data type, enclosed in parenthesis immediately following the data type name.

datatype(length)

Several data types that have only one legal length, ORACLE DATETIME and TINYINT for example, have default lengths that are used, and therefore do not require a length parameter value.

datatype

All columns in a table, except for the last column, must have an offset of 65,535 bytes or less. This means that there may be only one data type with a length greater than 65,535 AND it must be the last column in the table definition. Therefore, there can be only one column per table, the last column, of any of the following data types: CSTRING with a length of 32,768 bytes or more, CLOB, OMNIDEX CLOB, BLOB, or OMNIDEX BLOB.

Backward Compatibility

Beginning with OMNIDEX version 4.1, data type declarations in the OMNIDEX environment catalog were changed to more closely match native database syntax. Specifically, declared lengths are now enclosed in parenthesis or omitted when defaults apply, and support for more data types has been added, like DOUBLE and TINYINT.

DATATYPE datatype(n)

Previous verions of OMNIDEX required a LENGTH keyword followed by the length, and data types like DOUBLE and TINYINT were declared as FLOAT LENGTH 8 and INTEGER LENTH 1, respectively.

The old declaractions are still supported for backward compatibility. However, DISC recommends using the new syntax in all new installations and converting old installations to use the new syntax. An easy way to convert an existing installation using the old syntax, to the new syntax is to use OADECOMP to decompile the existing environment catalog into an editable source file or use OAHELPER to generate a new environment source file.

When using the old style to declare data types, the length value is required for all data types.

DATATYPE datatype LENGTH n

Length values can be different when using the old syntax. See Data Types Quick Reference for a side-by-side comparison.

Data Type Quick Reference

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