What Is Primitive Data Type?

Raw data is data in the user database, or various data stored and used by the end user. It is unprocessed or simplified data. These data may or may not be machine-readable. It constitutes the data of physical existence. There are many forms of raw data, such as text data, image data, audio data, or several types of data.

In the database: Raw data, also called user data, is unprocessed or simplified data, and this data may or may not be machine-readable. It constitutes the data of physical existence. There are generally a few basic data types in a database.

Character type char [(length)] fixed-length characters up to 2000 bytes varchar2 [(length)] variable-length character data types, up to 4000 bytes NCHAR [(length)] fixed-length character data types, by international Character language (national language support, NLS) character set characters, up to 2000 bytes LONG variable length character data type up to 2GB
RAW raw binary data type, up to 2000 bytes long raw raw binary data type, up to 2GB
A 12-byte address in the rawid database. It is used to locate a row on the disk and the object urawid. The common rawid is used for tables and is a representation of the row primary key.

Large object blob Large raw binary object, maximum length 4GB
clob large character object, maximum length 4GB
nclob is a large character data consisting of NLS character set characters, with a maximum length of 4GB
bfile provides access to data stored outside the oracle database

The quality of the original data has a lot to do with the later reading and processing of the data. At present, the research on the original data mainly focuses on the data acquisition and data compression. Many methods have been proposed in this regard. For example, SA R original data compression algorithm based on lifting wavelet belongs to transform coding. Unlike direct coding method, transform coding first transforms the original data and then quantizes the transform coefficients. The purpose of the transformation is to map the pixel array in the spatial domain into an irrelevant and compact energy distribution transform coefficient matrix. At this time, a small number of large transformation coefficients represent the most important energy component of the image towel, and a small number of small transformation coefficients represent some unimportant details. Word to describe the main energy represented by the large coefficient to achieve a high compression ratio. ^[3]