A Comprehensive Guide to Data Types in Oracle (2024)

FAQs

How many types of data types are there in Oracle? ›

Oracle has 8 character datatypes CHAR , NCHAR , VARCHAR , VARCHAR2 , and NVARCHAR , CLOB , NCLOB , and LONG . CHAR and VARCHAR2 are more important. VARCHAR2 is used to store variable-length character strings, while CHAR is used to store fixed-length character strings.

In SQL, you could could get multiple 4000 character pieces by using DBMS_LOB. SUBBSTR(field,4000,4001), DBMS_LOB. SUBBSTR(field,4000,8001), etc.

The datetime data types are DATE , TIMESTAMP , TIMESTAMP WITH TIME ZONE, and TIMESTAMP WITH LOCAL TIME ZONE . Values of datetime data types are sometimes called datetimes. The interval data types are INTERVAL YEAR TO MONTH and INTERVAL DAY TO SECOND .

Most modern computer languages recognize five basic categories of data types: Integral, Floating Point, Character, Character String, and composite types, with various specific subtypes defined within each broad category.

The simplest way to check the data type of an object in Python is to use the built-in type() function. This function returns the data type of the given object. In the example above, the type() function returns the data type of each object, and we can see the output displayed as <class 'data_type'> .

RAW. The RAW datatype is used for binary data or byte strings that are not to be interpreted by Oracle, for example, to store graphics character sequences. The maximum length of a RAW column is 2000 bytes.

When the VARCHAR2 data type is explicitly encountered in SQL statements, it is implicitly mapped to the VARCHAR data type. The maximum length for VARCHAR2 is 32672 BYTE or 8168 CHAR which is the same as the maximum length for VARCHAR of 32672 OCTETS or 8168 CODEUNITS32.

What is the maximum size of VARCHAR in Oracle? ›

The simplest way to manage instance memory is to allow the Oracle Database instance to automatically manage and tune it for you. To do so (on most platforms), you set only a target memory size initialization parameter ( MEMORY_TARGET ) and optionally a maximum memory size initialization parameter ( MEMORY_MAX_TARGET ).

The date/time precision in Microsoft SQL Server is 1/300th of a second. Oracle has the data type TIMESTAMP which has a precision of 1/100000000th of a second. Oracle also has a DATE data type that stores date and time values accurate to one second. SQL Developer has a default mapping to the DATE data type.

Oracle stores dates in an internal numeric format representing the century, year, month, day, hours, minutes, seconds. The default date format is DD-MON-YY. SYSDATE is a function returning date and time.

No, datetime is not a recognised data type in Oracle. The valid data types are listed in the documentation, which has a section on datetime and interval data types: The datetime data types are DATE , TIMESTAMP , TIMESTAMP WITH TIME ZONE , and TIMESTAMP WITH LOCAL TIME ZONE .

The data type is a guideline for SQL to understand what type of data is expected inside of each column, and it also identifies how SQL will interact with the stored data. In MySQL there are three main data types: string, numeric, and date and time.

PL/SQL provides many predefined datatypes. For instance, you can choose from integer, floating point, character, Boolean, date, collection, reference, and large object (LOB) types. PL/SQL also lets you define your own subtypes. This chapter covers the basic types used frequently in PL/SQL programs.

There is an absolute Oracle maximum of 65533 files in a database and usually 1022 files in a tablespace.