How do you set up partitioning by year when most fact tables have a datetime2 data type? - sql-server

Question

We're using SQL Server 2019. Our fact tables utilize datetime2 but I want to partition on year.
I don't have sysadmin privs so I can't set up different filegroups. I can create partition functions and partition schemes, but it isn't clear to me how to set up the partition scheme so that when I partition the table on ActivityLog for example that it will store entries in their respective year partition.
I've searched the web and haven't found answers as to how it all works.

Answer 1

Partitioning by year on a datetime2 column in a fact table can be a useful technique for managing large data sets, improving query performance, and reducing maintenance costs. Here are the steps to set up partitioning by year:
Define a partition function: A partition function defines the ranges or
boundaries for partitioning the data. In this case, you would define a
partition function that partitions the data by year. For example, the
following code creates a partition function that partitions the data by
year:
CREATE PARTITION FUNCTION pfFactTableByYear (datetime2(0))
AS RANGE RIGHT FOR VALUES
('2010-01-01T00:00:00', '2011-01-01T00:00:00', '2012-01-01T00:00:00', '2013-01-01T00:00:00', '2014-01-01T00:00:00', '2015-01-01T00:00:00', '2016-01-01T00:00:00', '2017-01-01T00:00:00', '2018-01-01T00:00:00', '2019-01-01T00:00:00', '2020-01-01T00:00:00')
Define a partition scheme: A partition scheme maps the partition function to
a set of filegroups. In this case, you would define a partition scheme that
maps the partition function to a set of filegroups. For example, the
following code creates a partition scheme that maps the partition function
to a set of filegroups:
CREATE PARTITION SCHEME psFactTableByYear
AS PARTITION pfFactTableByYear
TO (fg2010, fg2011, fg2012, fg2013, fg2014, fg2015, fg2016, fg2017, fg2018, fg2019, fg2020)
Create the fact table with partitioning: You would create the fact table
with the partition scheme defined in step 2. For example, the following code
creates a fact table with partitioning by year:
CREATE TABLE FactTable
(
Id INT IDENTITY(1,1),
DateColumn datetime2(0) NOT NULL,
ValueColumn decimal(18,2) NOT NULL,
CONSTRAINT PK_FactTable PRIMARY KEY (Id, DateColumn)
)
ON psFactTableByYear(DateColumn)
This creates a fact table with a primary key that includes the partitioning column (DateColumn), and maps the partition scheme to the fact table's data filegroups.
Load data into the fact table: Once the fact table is created, you can load
data into it using standard INSERT statements.
Perform maintenance tasks: As time goes on, new partitions will need to be
created to accommodate new data. You can automate this process using
partition switching or by running a maintenance script that creates new
partitions on a regular basis. You may also want to periodically archive or
remove old data to keep the data set manageable.
Note that partitioning by year is just one option for partitioning a fact table, and the partition function and scheme would need to be adjusted accordingly for other partitioning strategies, such as partitioning by month, quarter, or some other time period.