Accessors
This section defines requirements to an
accessor implementation and introduces several
accessor types.
Requirements
Each accessor implementation:
- Defines a single format of the data for the access. Every accessor type returns and use only one data format.
- Provides read-only access to the data in the table types.
- Provides thepull()method for obtaining the values from the table.
- Is lightweight. Its constructors do not have computationally intensive operations such data copy, reading, or conversion. These operations are performed by methodpull().
- Thepull()method avoids data copy and conversion when it is possible to return the pointer to the memory block in the table. This is applicable for cases such as when the data format and data types of the data within the table are the same as the data format and data type for the access.
Accessor Types
oneDAL defines a set of accessor classes. Each class supports one
specific way of obtaining data from the table.
All accessor classes in oneDAL are listed below:
Accessor type | Description | List of supported types |
|---|---|---|
Provides access to the range of values within a single column as one
contiguous homogeneous block of memory. |