Number pl/sql

Number pl/sql DEFAULT

PL/SQL numeric data type tips

This is an excerpt from the book Advanced PL/SQL: The Definitive Reference by Boobal Ganesan.

Data type acts as a placeholder for the data and determines the limit, format and the range of the data we deal with. A data of a certain type cannot be placed in an unmatched data type, for e.g., A string data cannot be placed in a NUMBER data type. The figure Fig depicts the relationship between the data and its data type.

Fig Relationship between Data and Data type

There are four different types of data types in PL/SQL and they are explained below,

PL/SQL Scalar Data Types

The scalar data type is a linear atomic type with no variable components in it and holds a single literal value.

A subtype on the other hand is a derived form of the base type with an optional constraint on it. These can be either constrained or unconstrained.

There are four predefined scalar data types as explained below.

PL/SQL Numeric Data Types

PL/SQL supports an increasing variety of numeric data types for the mathematical calculation purposes. The different numeric data types are described below.

Number

This is the super-type for all the numeric data types available in PL/SQL. This stores positive, negative, zero and floating point numbers. This is an internal data type used by the system, thus, it is slower than the other numeric types. As the number data type is commonly available in other languages and as it is an internal type in Oracle, this is extremely portable at the cost of performance.

The prototype for the number data type is shown below,

Number [(precision [, scale])]

For an integer, the scale is zero, meaning that there is no decimal point value allowed and the precision ranges between 1 and 38, e.g.,

For a floating point number, the scale ranges between and with a default 0. E.g.,

Predefined Subtypes of Number Data Type

1.       Integer/ Int/ Smallint: Theseare internal data types as like the Number data type, but with an extra constraint of scale value as 0. This is similar to Number (38,0). This type is much slower than the Number data type as it has an extra constraint imposed on it.

2.       Numeric/ Decimal/ Dec: These are the same as Number data type, but with a fixed precision of 38 and a scale value of 0. This constraint can be changed by issuing a user defined precision and a scale of Number data type's range.

            E.g., Numeric = Number (38,0) and Numeric (29,3) = Number (29,3).

3.       Double Precision/ Float: These are floating point number data type with a maximum of digits (Rounded off to 38 digits).

E.g., Double Precision = Float () and Float = Float ().

4.       Real: These are floating point number data type with a maximum of 63 digits (Rounded off to 18 digits).

E.g., Real = Float (63).

 

Need to learn to program with PL/SQL?  For complete notes on programming in PL/SQL, we recommend the book Advanced PL/SQL: The Definitive Reference by Boobal Ganesan.

This is a complete book on PL/SQL with everything you need to know to write efficient and complex PL/SQL code.
Sours: http://www.dba-oracle.com/t_plsql_numeric_data_types.htm

PL/SQL - Data Types



In this chapter, we will discuss the Data Types in PL/SQL. The PL/SQL variables, constants and parameters must have a valid data type, which specifies a storage format, constraints, and a valid range of values. We will focus on the SCALAR and the LOB data types in this chapter. The other two data types will be covered in other chapters.

S.NoCategory & Description
1

Scalar

Single values with no internal components, such as a NUMBER, DATE, or BOOLEAN.

2

Large Object (LOB)

Pointers to large objects that are stored separately from other data items, such as text, graphic images, video clips, and sound waveforms.

3

Composite

Data items that have internal components that can be accessed individually. For example, collections and records.

4

Reference

Pointers to other data items.

PL/SQL Scalar Data Types and Subtypes

PL/SQL Scalar Data Types and Subtypes come under the following categories −

S.NoDate Type & Description
1

Numeric

Numeric values on which arithmetic operations are performed.

2

Character

Alphanumeric values that represent single characters or strings of characters.

3

Boolean

Logical values on which logical operations are performed.

4

Datetime

Dates and times.

PL/SQL provides subtypes of data types. For example, the data type NUMBER has a subtype called INTEGER. You can use the subtypes in your PL/SQL program to make the data types compatible with data types in other programs while embedding the PL/SQL code in another program, such as a Java program.

PL/SQL Numeric Data Types and Subtypes

Following table lists out the PL/SQL pre-defined numeric data types and their sub-types −

S.NoData Type & Description
1

PLS_INTEGER

Signed integer in range -2,,, through 2,,,, represented in 32 bits

2

BINARY_INTEGER

Signed integer in range -2,,, through 2,,,, represented in 32 bits

3

BINARY_FLOAT

Single-precision IEEE format floating-point number

4

BINARY_DOUBLE

Double-precision IEEE format floating-point number

5

NUMBER(prec, scale)

Fixed-point or floating-point number with absolute value in range 1E to (but not including) E A NUMBER variable can also represent 0

6

DEC(prec, scale)

ANSI specific fixed-point type with maximum precision of 38 decimal digits

7

DECIMAL(prec, scale)

IBM specific fixed-point type with maximum precision of 38 decimal digits

8

NUMERIC(pre, secale)

Floating type with maximum precision of 38 decimal digits

9

DOUBLE PRECISION

ANSI specific floating-point type with maximum precision of binary digits (approximately 38 decimal digits)

10

FLOAT

ANSI and IBM specific floating-point type with maximum precision of binary digits (approximately 38 decimal digits)

11

INT

ANSI specific integer type with maximum precision of 38 decimal digits

12

INTEGER

ANSI and IBM specific integer type with maximum precision of 38 decimal digits

13

SMALLINT

ANSI and IBM specific integer type with maximum precision of 38 decimal digits

14

REAL

Floating-point type with maximum precision of 63 binary digits (approximately 18 decimal digits)

Following is a valid declaration −

DECLARE num1 INTEGER; num2 REAL; num3 DOUBLE PRECISION; BEGIN null; END; /

When the above code is compiled and executed, it produces the following result −

PL/SQL procedure successfully completed

PL/SQL Character Data Types and Subtypes

Following is the detail of PL/SQL pre-defined character data types and their sub-types −

S.NoData Type & Description
1

CHAR

Fixed-length character string with maximum size of 32, bytes

2

VARCHAR2

Variable-length character string with maximum size of 32, bytes

3

RAW

Variable-length binary or byte string with maximum size of 32, bytes, not interpreted by PL/SQL

4

NCHAR

Fixed-length national character string with maximum size of 32, bytes

5

NVARCHAR2

Variable-length national character string with maximum size of 32, bytes

6

LONG

Variable-length character string with maximum size of 32, bytes

7

LONG RAW

Variable-length binary or byte string with maximum size of 32, bytes, not interpreted by PL/SQL

8

ROWID

Physical row identifier, the address of a row in an ordinary table

9

UROWID

Universal row identifier (physical, logical, or foreign row identifier)

PL/SQL Boolean Data Types

The BOOLEAN data type stores logical values that are used in logical operations. The logical values are the Boolean values TRUE and FALSE and the value NULL.

However, SQL has no data type equivalent to BOOLEAN. Therefore, Boolean values cannot be used in −

  • SQL statements
  • Built-in SQL functions (such as TO_CHAR)
  • PL/SQL functions invoked from SQL statements

PL/SQL Datetime and Interval Types

The DATE datatype is used to store fixed-length datetimes, which include the time of day in seconds since midnight. Valid dates range from January 1, BC to December 31, AD.

The default date format is set by the Oracle initialization parameter NLS_DATE_FORMAT. For example, the default might be 'DD-MON-YY', which includes a two-digit number for the day of the month, an abbreviation of the month name, and the last two digits of the year. For example, OCT

Each DATE includes the century, year, month, day, hour, minute, and second. The following table shows the valid values for each field −

Field NameValid Datetime ValuesValid Interval Values
YEAR to (excluding year 0)Any nonzero integer
MONTH01 to 120 to 11
DAY01 to 31 (limited by the values of MONTH and YEAR, according to the rules of the calendar for the locale)Any nonzero integer
HOUR00 to 230 to 23
MINUTE00 to 590 to 59
SECOND00 to (n), where 9(n) is the precision of time fractional seconds0 to (n), where 9(n) is the precision of interval fractional seconds
TIMEZONE_HOUR to 14 (range accommodates daylight savings time changes)Not applicable
TIMEZONE_MINUTE00 to 59Not applicable
TIMEZONE_REGIONFound in the dynamic performance view V$TIMEZONE_NAMESNot applicable
TIMEZONE_ABBRFound in the dynamic performance view V$TIMEZONE_NAMESNot applicable

PL/SQL Large Object (LOB) Data Types

Large Object (LOB) data types refer to large data items such as text, graphic images, video clips, and sound waveforms. LOB data types allow efficient, random, piecewise access to this data. Following are the predefined PL/SQL LOB data types −

Data TypeDescriptionSize
BFILEUsed to store large binary objects in operating system files outside the database.System-dependent. Cannot exceed 4 gigabytes (GB).
BLOBUsed to store large binary objects in the database.8 to terabytes (TB)
CLOBUsed to store large blocks of character data in the database.8 to TB
NCLOBUsed to store large blocks of NCHAR data in the database.8 to TB

PL/SQL User-Defined Subtypes

A subtype is a subset of another data type, which is called its base type. A subtype has the same valid operations as its base type, but only a subset of its valid values.

PL/SQL predefines several subtypes in package STANDARD. For example, PL/SQL predefines the subtypes CHARACTER and INTEGER as follows −

SUBTYPE CHARACTER IS CHAR; SUBTYPE INTEGER IS NUMBER(38,0);

You can define and use your own subtypes. The following program illustrates defining and using a user-defined subtype −

DECLARE SUBTYPE name IS char(20); SUBTYPE message IS varchar2(); salutation name; greetings message; BEGIN salutation := 'Reader '; greetings := 'Welcome to the World of PL/SQL'; dbms_output.put_line('Hello ' || salutation || greetings); END; /

When the above code is executed at the SQL prompt, it produces the following result −

Hello Reader Welcome to the World of PL/SQL PL/SQL procedure successfully completed.

NULLs in PL/SQL

PL/SQL NULL values represent missing or unknown data and they are not an integer, a character, or any other specific data type. Note that NULL is not the same as an empty data string or the null character value '\0'. A null can be assigned but it cannot be equated with anything, including itself.

Sours: https://www.tutorialspoint.com/plsql/plsql_data_types.htm
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Oracle / PLSQL: Data Types

dateA date between Jan 1, BC and Dec 31, AD.A date between Jan 1, BC and Dec 31, AD.A date between Jan 1, BC and Dec 31, AD. timestamp (fractional seconds precision)fractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)

Includes year, month, day, hour, minute, and seconds.

For example:
timestamp(6)

timestamp (fractional seconds precision) with time zonefractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)

Includes year, month, day, hour, minute, and seconds; with a time zone displacement value.

For example:
timestamp(5) with time zone

timestamp (fractional seconds precision) with local time zonefractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)fractional seconds precision must be a number between 0 and 9. (default is 6)Includes year, month, day, hour, minute, and seconds; with a time zone expressed as the session time zone.

For example:
timestamp(4) with local time zone

interval year
(year precision)
to monthyear precision is the number of digits in the year. (default is 2)year precision is the number of digits in the year. (default is 2)year precision is the number of digits in the year. (default is 2)

Time period stored in years and months.

For example:
interval year(4) to month

interval day
(day precision)
to second (fractional seconds precision)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

day precision must be a number between 0 and 9. (default is 2)

fractional seconds precision must be a number between 0 and 9. (default is 6)

Time period stored in days, hours, minutes, and seconds.

For example:
interval day(2) to second(6)

Sours: https://www.techonthenet.com/oracle/datatypes.php
PL/SQL tutorial 39: How To Create PL/SQL Functions in Oracle Database By Manish Sharma

What is PL/SQL Datatypes?

Data Types in PL/SQL are used to define how the data will be stored, handled, and treated by Oracle during the data storage and processing. Data types are associated with the specific storage format and range constraints. In Oracle, each value or constant is assigned with a data type.

The main difference between PL/SQL and SQL data types is, SQL data type are limited to table column while the PL/SQL data types are used in the PL/SQL blocks. More on this later in the tutorial.

Following is the diagram of different Oracle PL/SQL Data Types:

Different Data Types in PL/SQL

Different Data Types in PL/SQL

In this PL/SQL Data Types Tutorial , you will learn-

PL/SQL CHARACTER Data Type

This data type basically stores alphanumeric characters in string format.

The literal values should always be enclosed in single quotes while assigning them to CHARACTER data type.

This character data type is further classified as follows:

  • CHAR Data type (fixed string size)
  • VARCHAR2 Data type (variable string size)
  • VARCHAR Data type
  • NCHAR (native fixed string size)
  • NVARCHAR2 (native variable string size)
  • LONG and LONG RAW
Data TypeDescriptionSyntax
CHARThis data type stores the string value, and the size of the string is fixed at the time of declaring the variable.
  • Oracle would be blank-padded the variable if the variable didn&#;t occupy the entire size that has been declared for it, Hence Oracle will allocate the memory for declared size even if the variable didn&#;t occupy it fully.
  • The size restriction for this data type is bytes.
  • CHAR data type is more appropriate to use where ever fixed the size of data will be handled.
grade CHAR; manager CHAR (10):= 'guru99';

Syntax Explanation:

  • The first declaration statement declared the variable &#;grade&#; of CHAR data type with the maximum size of 1 byte (default value).
  • The second declaration statement declared the variable &#;manager&#; of CHAR data type with the maximum size of 10 and assigned the value &#;guru99&#; which is of 6 bytes. Oracle will allocate the memory of 10 bytes rather than 6 bytes in this case.
VARCHAR2This data type stores the string, but the length of the string is not fixed.
  • The size restriction for this data type is bytes for table column size and bytes for variables.
  • The size is defined for each variable at the time of variable declaration.
  • But Oracle will allocate memory only after the variable is defined, i.e., Oracle will consider only the actual length of the string that is stored in a variable for memory allocation rather than the size that has been given for a variable in the declaration part.
  • It is always good to use VARCHAR2 instead of CHAR data type to optimize the memory usage.
manager VARCHAR2(10) := ‘guru99';

Syntax Explanation:

  • The above declaration statement declared the variable &#;manager&#; of VARCHAR2 data type with the maximum size of 10 and assigned the value &#;guru99&#; which is of 6 bytes. Oracle will allocate memory of only 6 bytes in this case.
VARCHARThis is synonymous with the VARCHAR2 data type.
  • It is always a good practice to use VARCHAR2 instead of VARCHAR to avoid behavioral changes.
manager VARCHAR(10) := ‘guru99';

Syntax Explanation:

  • The above declaration statement declared the variable &#;manager&#; of VARCHAR data type with the maximum size of 10 and assigned the value &#;guru99&#; which is of 6 bytes. Oracle will allocate memory of only 6 bytes in this case. (Similar to VARCHAR2)
NCHAR This data type is same as CHAR data type, but the character set will of the national character set.
  • This character set can be defined for the session using NLS_PARAMETERS.
  • The character set can be either UTF16 or UTF8.
  • The size restriction is bytes.
native NCHAR(10);

Syntax Explanation:

  • The above declaration statement declares the variable &#;native&#; of NCHAR data type with the maximum size of
  • The length of this variable depends upon the (number of lengths) per byte as defined in the character set.
NVARCHAR2 This data type is same as VARCHAR2 data type, but the character set will be of the national character set.
  • This character set can be defined for the session using NLS_PARAMETERS.
  • The character set can be either UTF16 or UTF8.
  • The size restriction is bytes.
Native var NVARCHAR2(10):='guru99';

Syntax Explanation:

  • The above declaration statement declares the variable &#;Native_var&#; of NVARCHAR2 data type with the maximum size of
LONG and LONGRAW

This data type is used to store large text or raw data up to the maximum size of 2GB.

  • These are mainly used in the data dictionary.
  • LONG data type is used to store character set data, while LONG RAW is used to store data in binary format.
  • LONG RAW data type accepts media objects, images, etc. whereas LONG works only on data that can be stored using character set.
Large_text LONG; Large_raw LONG RAW;

Syntax Explanation:

  • The above declaration statement declares the variable &#;Large_text&#; of LONG data type and &#;Large_raw&#; of LONG RAW data type.

Note: Using LONG data type is not recommended by Oracle. Instead, LOB data type should be preferred.

PL/SQL NUMBER Data Type

This data type stores fixed or floating point numbers up to 38 digits of precision. This data type is used to work with fields which will contain only number data. The variable can be declared either with precision and decimal digit details or without this information. Values need not enclose within quotes while assigning for this data type.

A NUMBER(8,2); B NUMBER(8); C NUMBER;

Syntax Explanation:

  • In the above, the first declaration declares the variable &#;A&#; is of number data type with total precision 8 and decimal digits 2.
  • The second declaration declares the variable &#;B&#; is of number data type with total precision 8 and no decimal digits.
  • The third declaration is the most generic, declares variable &#;C&#; is of number data type with no restriction in precision or decimal places. It can take up to a maximum of 38 digits.

PL/SQL BOOLEAN Data Type

This data type stores the logical values. Oracle Boolean Data Type represents either TRUE or FALSE and mainly used in conditional statements. Values need not enclose within quotes while assigning for this data type.

Var1 BOOLEAN;

Syntax Explanation:

  • In the above, variable &#;Var1&#; is declared as BOOLEAN data type. The output of the code will be either true or false based on the condition set.

PL/SQL DATE Data Type

This data type stores the values in date format, as date, month, and year. Whenever a variable is defined with DATE data type along with the date it can hold time information and by default time information is set to if not specified. Values need to enclose within quotes while assigning for this data type.

The standard Oracle time format for input and output is &#;DD-MON-YY&#; and it is again set at NLS_PARAMETERS (NLS_DATE_FORMAT) at the session level.

newyear DATE:='JAN'; current_date DATE:=SYSDATE;

Syntax Explanation:

  • In the above, variable &#;newyear&#; is declared as DATE data type and assigned the value of Jan 1st, date.
  • The second declaration declares the variable current_date as DATE data type and assigned the value with current system date.
  • Both these variable holds the time information.

PL/SQL LOB Data Type

This data type is mainly used to store and manipulate large blocks of unstructured data&#;s like images, multimedia files, etc. Oracle prefers LOB instead of the a LONG data type as it is more flexible than the LONG data type. The below are the few main advantage of LOB over LONG data type.

  • The number of column in a table with LONG data type is limited to 1, whereas a table has no restriction on a number of columns with LOB data type.
  • The data interface tool accepts LOB data type of the table during data replication, but it omits LONG column of the table. These LONG columns need to be replicated manually.
  • The size of the LONG column is 2GB, whereas LOB can store up to TB.
  • Oracle is constantly improving the LOB data type in each of their releases according to the modern requirement, whereas LONG data type is constant and not getting many updates.

So, it is always good to use LOB data type instead of the LONG data type. Following are the different LOB data types. They can store up to the size of terabytes.

  1. BLOB
  2. CLOB and NCLOB
  3. BFILE
Data TypeDescriptionSyntax
BLOB

This data type stores the LOB data in the binary file format up to the maximum size of TB. This doesn&#;t store data based on the character set details, so that it can store the unstructured data such as multimedia objects, images, etc.

Binary_data BLOB;

Syntax Explanation:

  • In the above, variable &#;Binary_data&#; is declared as a BLOB.
CLOB and NCLOB

CLOB data type stores the LOB data into the character set, whereas NCLOB stores the data in the native character set. Since these data types use character set based storage, these cannot store the data like multimedia, images, etc. that cannot be put into a character string. The maximum size of these data types is TB.

Charac_data CLOB;

Syntax Explanation:

  • In the above, variable &#;Charac_data&#; is declared as CLOB data type.
BFILE
  • BFILE are the data types that stored the unstructured binary format data outside the database as an operating-system file.
  • The size of BFILE is to a limited operating system, and they are read-only files and can&#;t be modified.

Summary

We have covered the different simple data types that are available in PL/SQL along with their syntax. We will learn about complex data types in further topics.

Sours: https://www.gurucom/pl-sql-data-types.html

Pl/sql number

What is the size of Number data type in Oracle PL\SQL with out precision and scale suplied?

One of the guidelines in my new project is to specify precision & scale along with the NUMBER in Oracle PL\SQL. The developer handbook says if this is not specified a default size of 22 bytes is allocated for every variable.

While I understand it is important to specify precision & scale where ever possible. I don't seem to agree that 22 bytes are allocated if the precision is not supplied.

http://docs.oracle.com/cd/B_01/server/b/datatype.htm#CNCPT

From the Oracle documentations:

"Internal Numeric Format

Oracle Database stores numeric data in variable-length format. Each value is stored in scientific notation, with 1 byte used to store the exponent and up to 20 bytes to store the mantissa. The resulting value is limited to 38 digits of precision. Oracle Database does not store leading and trailing zeros.
For example, the number is stored in a format similar to x 102, with 1 byte used to store the exponent(2) and 2 bytes used to store the three significant digits of the mantissa(4,1,2). Negative numbers include the sign in their length."

I sent the above documentation to the database architect, but he doesn't seem to agree with me.

If we don't specify precision & scale for a NUMBER datatype in oracle pl\sql will it take 22 bytes or just enough bytes to store the value assigned to it?

Sours: https://stackoverflow.com/questions//what-is-the-size-of-number-data-type-in-oracle-pl-sql-with-out-precision-and-sca
Jak tworzyć funkcję w PL/SQL i czym różni się funkcja od procedury składowanej?

Performance of Numeric Data Types in PL/SQL

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Oracle provide a variety of numeric data types that have differing performance characteristics. This article demonstrates the performance differences between the basic integer and real number datatypes.

NUMBER Data Type

The data type is the supertype of all numeric datatypes. It is an internal type, meaning the Oracle program performs the mathematical operations, making it slower, but extremely portable. All the tests in this article will compare the performance of other types with the data type.

Integer Data Types

The following code compares the performance of some integer data types with that of the data type.

SET SERVEROUTPUT ON DECLARE l_number1 NUMBER := 1; l_number2 NUMBER := 1; l_integer1 INTEGER := 1; l_integer2 INTEGER := 1; l_pls_integer1 PLS_INTEGER := 1; l_pls_integer2 PLS_INTEGER := 1; l_binary_integer1 BINARY_INTEGER := 1; l_binary_integer2 BINARY_INTEGER := 1; l_simple_integer1 SIMPLE_INTEGER := 1; l_simple_integer2 SIMPLE_INTEGER := 1; l_loops NUMBER := ; l_start NUMBER; BEGIN -- Time NUMBER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_number1 := l_number1 + l_number2; END LOOP; DBMS_OUTPUT.put_line('NUMBER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time INTEGER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_integer1 := l_integer1 + l_integer2; END LOOP; DBMS_OUTPUT.put_line('INTEGER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time PLS_INTEGER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_pls_integer1 := l_pls_integer1 + l_pls_integer2; END LOOP; DBMS_OUTPUT.put_line('PLS_INTEGER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time BINARY_INTEGER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_binary_integer1 := l_binary_integer1 + l_binary_integer2; END LOOP; DBMS_OUTPUT.put_line('BINARY_INTEGER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time SIMPLE_INTEGER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_simple_integer1 := l_simple_integer1 + l_simple_integer2; END LOOP; DBMS_OUTPUT.put_line('SIMPLE_INTEGER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); END; / NUMBER : 24 hsecs INTEGER : 44 hsecs PLS_INTEGER : 9 hsecs BINARY_INTEGER : 9 hsecs SIMPLE_INTEGER : 8 hsecs PL/SQL procedure successfully completed. SQL>

From this we can make a number of conclusions:

  • : As mentioned previously, since is an internal datatype, it is not the fastest of the numeric types.
  • : Like , the type is an internal type, but the extra constraints on this datatype make it substantially slower than . If possible, you should avoid constrained internal datatypes.
  • : This type uses machine arithmetic, making it much faster than the internal datatypes. If in doubt, you should use for integer variables.
  • : Prior to Oracle 10g, was an internal type with performance characteristics worse than the datatype. From Oracle 10g upward is identical to .
  • : This subtype of was introduced in Oracle 11g. In interpreted mode it has similar performance to and , but in natively compiled code it is typically about twice as fast as those types. You can read more about the data type here.

There are additional predefined subtypes of , listed here.

Real Number Data Types

Oracle 10g introduced the and data types to handle real numbers. Both new types use machine arithmetic, making them faster than the data type, as shown in the following example.

SET SERVEROUTPUT ON DECLARE l_number1 NUMBER := ; l_number2 NUMBER := ; l_binary_float1 BINARY_FLOAT := ; l_binary_float2 BINARY_FLOAT := ; l_simple_float1 SIMPLE_FLOAT := ; l_simple_float2 SIMPLE_FLOAT := ; l_binary_double1 BINARY_DOUBLE := ; l_binary_double2 BINARY_DOUBLE := ; l_simple_double1 SIMPLE_DOUBLE := ; l_simple_double2 SIMPLE_DOUBLE := ; l_loops NUMBER := ; l_start NUMBER; BEGIN -- Time NUMBER. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_number1 := l_number1 + l_number2; END LOOP; DBMS_OUTPUT.put_line('NUMBER : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time BINARY_FLOAT. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_binary_float1 := l_binary_float1 + l_binary_float2; END LOOP; DBMS_OUTPUT.put_line('BINARY_FLOAT : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time SIMPLE_FLOAT. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_simple_float1 := l_simple_float1 + l_simple_float2; END LOOP; DBMS_OUTPUT.put_line('SIMPLE_FLOAT : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time BINARY_DOUBLE. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_binary_double1 := l_binary_double1 + l_binary_double2; END LOOP; DBMS_OUTPUT.put_line('BINARY_DOUBLE : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); -- Time SIMPLE_DOUBLE. l_start := DBMS_UTILITY.get_time; FOR i IN 1 .. l_loops LOOP l_simple_double1 := l_simple_double1 + l_simple_double2; END LOOP; DBMS_OUTPUT.put_line('SIMPLE_DOUBLE : ' || (DBMS_UTILITY.get_time - l_start) || ' hsecs'); END; / NUMBER : 26 hsecs BINARY_FLOAT : 14 hsecs SIMPLE_FLOAT : 14 hsecs BINARY_DOUBLE : 15 hsecs SIMPLE_DOUBLE : 14 hsecs PL/SQL procedure successfully completed. SQL>

Both and out-perform the data type, but the fact they use machine arithmetic can potentially make them less portable. The same mathematical operations performed on two different underlying architectures may result in minor rounding errors. If portability is your primary concern, then you should use the type, otherwise you can take advantage of these types for increased performance.

Similar to , and provide improved performance in natively compiled code because of the removal of NULL checking.

For more information see:

Hope this helps. Regards Tim

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Sours: https://oracle-base.com/articles/misc/performance-of-numeric-data-types-in-plsql

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Summary: in this tutorial, you will learn about the Oracle data type and how to use it to define numeric columns for a table.

Introduction to Oracle data type

The Oracle data type is used to store numeric values that can be negative or positive. The following illustrates the syntax of the data type:

Code language:SQL (Structured Query Language)(sql)

The Oracle data type has precision and scale.

  • The precision is the number of digits in a number. It ranges from 1 to
  • The scale is the number of digits to the right of the decimal point in a number. It ranges from to

For example, the number has a precision of 6 and a scale of 2. So to store this number, you need .

Both precision and scale are in decimal digits and optional. If you skip the precision and scale, Oracle uses the maximum range and precision for the number.

For example, the following form defines a number that can store numeric values with the maximum range and precision:

Code language:SQL (Structured Query Language)(sql)

The following syntax defines a fixed-point number:

Code language:SQL (Structured Query Language)(sql)

To define an integer, you use the following form:

Code language:SQL (Structured Query Language)(sql)

The above form represents a fixed-point number with precision p and scale of zero, which is equivalent to the following:

Code language:SQL (Structured Query Language)(sql)

Oracle allows the scale to be negative, for example the following number will round the numeric value to hundreds.

Code language:SQL (Structured Query Language)(sql)

Note that if you insert a number into a column and the number exceeds precision p, Oracle will issue an error. However, if the number exceeds the scale s, Oracle will round the value.

Oracle data type examples

The following statement creates a table named that consists of a numeric column:

Code language:SQL (Structured Query Language)(sql)

The following statements insert three numbers into the table:

Code language:SQL (Structured Query Language)(sql)

In this example:

  • The first value was inserted successfully because the number was in the range defined for the column.
  • The second value was rounded down and the third value was rounded up because the column accepted only numbers with two decimal point places.

The following example inserts the maximum and minimum values that the can accept:

Code language:SQL (Structured Query Language)(sql)

The following example causes an error because the inserted value exceeds the precision defined for the column.

Code language:SQL (Structured Query Language)(sql)

Consider the following example:

Code language:SQL (Structured Query Language)(sql)

In this example, the value was rounded up which resulted in a number that exceeded the precision defined for the column.

Oracle data type aliases

Oracle contains a number of aliases that you can use for define numeric columns as shown in the following table:

ANSI data typeOracle NUMBER data type
INTNUMBER(38)
SMALLINTNUMBER(38)
NUMBER(p,s)NUMBER(p,s)
DECIMAL(p,s)NUMBER(p,s)

Note that , , , and are just aliases. They are not the real data types. Internally, Oracle maps these aliases to the corresponding data type.

In this tutorial, you have learned the Oracle data type and how to use it to define numeric columns for a table.

Sours: https://www.oracletutorial.com/oracle-basics/oracle-number-data-type/


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