Variable LengthType Mapping

You can apply type mapping to columns of type VARCHAR2 and NVARCHAR2 and variable-length analysis for JSON columns. It is controlled by the var field in the –typeMap command line option.

The var field accepts any one of the following values:

Values Description

0 This is the default value. No mapping applies; the columns in the TimesTen database retain the same type and length as in the Oracle database.

Values	Description
`0`	This is the default value. No mapping applies; the columns in the TimesTen database retain the same type and length as in the Oracle database.
`1`	It enables variable-length analysis for `VARCHAR2`, `NVARCHAR2`, and `JSON` columns. For `VARCHAR2` and `NVARCHAR2`, the analysis may reduce the generated TimesTen column size. For `JSON`, the analysis validates the maximum value against the `4` MiB TimesTen `JSON` limit. The data in each column of the Oracle database is analyzed to determine: The length semantics (char or byte) The maximum stored data length The average stored length Any column where the maximum stored data length (accounting for length semantics) is less than the declared maximum size is imported as a column with the same data type and length semantics but with a defined maximum length equal to the maximum stored data length (see Padding). Use this mapping with caution. It remains valid only for the data values that currently exist in the Oracle database tables. If the data changes applies the mapping, the new values may no longer satisfy the criteria used to determine the mapping. However, this approach can significantly reduce memory usage, especially for very large data sets containing millions of rows, making it a good option in many scenarios.

1

It enables variable-length analysis for VARCHAR2, NVARCHAR2, and JSON columns. For VARCHAR2 and NVARCHAR2, the analysis may reduce the generated TimesTen column size. For JSON, the analysis validates the maximum value against the 4 MiB TimesTen JSON limit. The data in each column of the Oracle database is analyzed to determine:

The length semantics (char or byte)
The maximum stored data length
The average stored length

Any column where the maximum stored data length (accounting for length semantics) is less than the declared maximum size is imported as a column with the same data type and length semantics but with a defined maximum length equal to the maximum stored data length (see Padding).

Use this mapping with caution. It remains valid only for the data values that currently exist in the Oracle database tables. If the data changes applies the mapping, the new values may no longer satisfy the criteria used to determine the mapping. However, this approach can significantly reduce memory usage, especially for very large data sets containing millions of rows, making it a good option in many scenarios.