Generating Partition Function – sp_tblCreatePartitionFunction available don GitHub

If you are working with large databases you have come to situation when you need to partition the large tables.

To be able to partition a table, you need to create a Partition Function. Creation of Partition Function is quite easy, however if you need to create a larger number of partitions at initial phase, it can be pretty annoying as you have to define all the ranges for each partition. Also it is easy to make a type in the list of boundary values and as a result create a partition function with wrong partition alignment.

To simplify that process I’m presenting here a stored procedure which takes care about that and generates the partition function automatically based on input parameters

sp_tblCreatePartitionFunction

As mentioned above, the sp_tblCreatePartitionFunction takes care about generation of the partition function based on input parameters.

You can find complete source code in my SQL-Scripts project on GitHub under the TablesManagement\Partitioning folder.

The stored procedure provides support for generation of ranges based on smallint, int, bigint, date, datetime and datetime2 data types.

Stored procedure generates a partition function with boundary values between @rangeStart and @rangeEnd parameters.

The stored procedure is marked as system stored procedure in the script so it means that it can operate in the context of the current user database.

Parameters

The input parameters define the ranges and the way how the partition function is generated

The available input parameters for the function are @pfName, @rangeStart, @rangeEnd, @boundaryType, @incrementValue, @incrementUnit, @useIntegerDates, @integerFormatType and @printScriptOnly

@pfName

Defines the partition function Name. the parameter data type is nvarchar(128) which corresponds to sysname.

@rangeStart

Defines the starting range for generation of the partition function. The parameter is sql_variant. You have to pass parameter of supported data type for the range. As mentioned above the supported data types are smallint, int, bigint, date, datetime and datetime2.

To simplify specification of the range, you can pass the parameter as string. If the value passed as string represents a DateTime it is automatically converted to datetime data type.

You can also pass a value with a data type specifier. The data type specifier must be first character of the string and the value must follow. The supported data type specifiers are 'D' - date, 'T' - datetime, 'B' - bigint, 'I' - int and 'S' - smallint.

Below are some examples of supported strings passed as @rangeStart :

Sample value Result
'2016-01-01' Converted to datetime 2016-01-01
20160101 Converted to datetime 2016-01-01
D2016-01-01 Converted to date 2016-01-01
T20160101 Converted to datetime 2016-01-01
B1010 Converted to bigint 100
I1010 Converted to int 100
S1010 Converted to smallint 100

The @rangeStart representing a date can be altered during the partition function generation based on the @incrementUnit parameter. The @rangeStart is shifted to the beginning of corresponding unit.. See the @incrementUnit parameter for details.

The @rangeStart is included in the generated ranges.

@rangeEnd

Represents then end of range which should be generated for the partition function. The supported data types are the same as for the @rangeStart. See the @rangeStart for details.

The @rangeEnd is inclusive in the range, but may not be included in the final generated partition function in dependency on the @incrementValue and @incrementUnit parameters. See those parameters for details.

@boundaryType

Specifies the boundary type of the boundary values for the partition function. It can be either LEFT or RIGHT. It defines whether the boundary value is included in the left or right partition respective to the boundary value. Default value is RIGHT.

@incrementValue

Defines increment of the boundary values. This means that the @rangeStart value is incremented by the @incrementValue until @rangeEnd is reached.

@incrementUnit

Specifies the unit of the increment. It is being used only for range values representing date. The allowed units are YEAR, MONTH, WEEK, ISO_WEEK, DAY.

In each iteration step the @rangeStart value is incremented by the @incrementValue number of @incrementUnit.

Also the @incrementUnit may have impact on the @rangeStart value. If the @rangeStart value does not point to the first day of respective unit, it is being automatically shifted to the beginning of corresponding unit based on the @rangeStart value.

Samples of @rangeStart shifting:

@rangeStart @incrementUnit @rangeStart shifted to
'2016-03-17' YEAR '2016-01-01'
'2016-03-17' MONTH '2016-03-01'
'2016-03-17' WEEK '2016-03-14'
'2016-01-01' ISO_WEEK '2015-12-28'

@useIntegerDates

Specifies whether boundary values representing dates in the partition function should be represented as int date types or corresponding date, datetime or datetime2 data type. In case of  @useIntegerDates = 0 the boundary value is always first day of corresponding @incrementUnit.

In case of @useIntegerDates = 1 the boundary value is expressed as integer number and the value representing the range depends on the @integerFormatType parameter. See the @integerFormatType for details

It is being used only for date ranges. Default value is 1.

@integerFormatType

Specifies integer format of date range value. When the partition function is being generated and date ranges are being used, the range value is internally always represented by a first day of corresponding rage. if the @useIntegerDate = 1 the final boundary value is generated based on the format type.

Supported format types are:

FormatType Boundary value formatting
1 yyyyMMdd For example 20160101
2 yyyyxx(x) where xxx(x) correspond to appropriate month, week or day within particular year. For example 2016053 represents a day 53 of year 2016. 201643 represents week or iso_week 43 in year 2016

Default value is 2.

@printScriptOnly

Specifies whether only the partition function CREATE script is being printed or the partition function is being automatically crated.

The default value is 1, this means that only script is printed.

Samples

Below are some sample usages of the stored procedure.

Sample 1

sp_tblCreatePartitionFunction
    @pfName = 'myPf'
   ,@rangeStart = 1
   ,@rangeEnd = 1001
   ,@boundaryType = 'RIGHT'
   ,@incrementvalue = 100
CREATE PARTITION FUNCTION [myPf](int) AS RANGE RIGHT FOR VALUES (
    1
   ,101
   ,201
   ,301
   ,401
   ,501
   ,601
   ,701
   ,801
   ,901
   ,1001
)

Sample 2

sp_tblCreatePartitionFunction
    @pfName = 'myPf'
   ,@rangeStart = '2016-01-01'
   ,@rangeEnd = '2020-12-31'
   ,@boundaryType = 'RIGHT'
   ,@incrementvalue = 1
   ,@incrementUnit = 'YEAR'
   ,@useIntegerDates = 1
   ,@integerFormatType = 2

CREATE PARTITION FUNCTION [myPf](int) AS RANGE RIGHT FOR VALUES (
    2016
   ,2017
   ,2018
   ,2019
   ,2020
)

Sample 3

sp_tblCreatePartitionFunction
    @pfName = 'myPf'
   ,@rangeStart = '2016-01-01'
   ,@rangeEnd = '2016-12-31'
   ,@boundaryType = 'LEFT'
   ,@incrementvalue = 1
   ,@incrementUnit = 'MONTH'
   ,@useIntegerDates = 1
   ,@integerFormatType = 2
CREATE PARTITION FUNCTION [myPf](int) AS RANGE LEFT FOR VALUES (
    20160101
   ,20160201
   ,20160301
   ,20160401
   ,20160501
   ,20160601
   ,20160701
   ,20160801
   ,20160901
   ,20161001
   ,20161101
   ,20161201
)

Sample 4

sp_tblCreatePartitionFunction
    @pfName = 'myPf'
   ,@rangeStart = '2016-01-01'
   ,@rangeEnd = '2016-12-31'
   ,@boundaryType = 'LEFT'
   ,@incrementvalue = 1
   ,@incrementUnit = 'MONTH'
   ,@useIntegerDates = 0
CREATE PARTITION FUNCTION [myPf](datetime) AS RANGE LEFT FOR VALUES (
    '20160101'
   ,'20160201'
   ,'20160301'
   ,'20160401'
   ,'20160501'
   ,'20160601'
   ,'20160701'
   ,'20160801'
   ,'20160901'
   ,'20161001'
   ,'20161101'
   ,'20161201'
)
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