PGB - PBR

PGB - PBR

 

 

In IBM DB2 for z/OS, partitioning is a technique used to divide a table into smaller, more manageable pieces called partitions. There are two main types of partitioning methods: partition by growth and partition by range.

 

Partition by growth (also known as "system-period temporal" or "SPT") is a type of partitioning that automatically creates new partitions as the data in the table grows. This method is typically used for large tables that are subject to high levels of insert activity and are expected to grow over time. With partition by growth, new partitions are created based on predefined thresholds, such as a maximum size or number of rows.

 

Partition by range (also known as "partitioned tables") is a type of partitioning that divides a table based on a specific column or set of columns. This method is typically used for large tables that need to be queried or searched based on a specific value or range of values. With partition by range, the table is divided into smaller partitions based on the values in the partitioning column(s), and each partition is assigned a range of values.

 

Partition by growth is used for tables that are subject to high levels of insert activity and are expected to grow over time, while partition by range is used for tables that need to be queried or searched based on specific values or ranges of values. Both methods offer benefits such as improved query performance, increased data manageability, and better availability.

 

Partition by growth is useful when you want to store historical data and you want to keep the current and historical data separate, for example keeping the last year data separate from the data older than a year. This way you can easily retrieve the current data, archive the historical data and delete it if it's not needed.

 

Partition by range is useful when you want to access the data based on a specific range, for example if you have a table that contains sales data and you want to retrieve the sales data for a specific quarter, you can use partition by range on the date column of the sales table. This way you can easily access the data for a specific range of dates without having to scan the whole table.

 

Both partition by growth and partition by range have their own advantages and disadvantages, and the choice between them depends on the specific use case and the requirements of the application. In general, partition by growth is more suitable for tables that are subject to high levels of insert activity and are expected to grow over time, while partition by range is more suitable for tables that need to be queried or searched based on specific values or ranges of values.

 

When implementing partition by growth on DB2 z/OS, it's important to consider the following:

 

•          The partitioning column or columns, which determine how the table will be partitioned.
•          The partitioning scheme, which determines the number and size of the partitions.
•          The partitioning granularity, which determines the frequency at which new partitions are created.
•          The partitioning history, which determines the number of historical partitions that will be retained.

On the other hand, when implementing partition by range on DB2 z/OS, it's important to consider the following:

 

•          The partitioning column or columns, which determine how the table will be partitioned.
•          The partitioning scheme, which determines the number and size of the partitions.
•          The partitioning range, which determines the range of values for each partition.
•          The partitioning key, which determines the order of the partitions.

It's important to note that both partition by growth and partition by range require a good understanding of the data, the access patterns and the growth patterns of the table. It's also important to consider the impact of partitioning on the overall performance of the database and the cost of maintaining the partitions.

 

Additionally, it is important to test the different partitioning methods and to monitor the performance of the table after partitioning to ensure that it meets the desired performance and scalability requirements.

 

In summary, partition by growth and partition by range are both powerful techniques that can help improve the performance, scalability, and manageability of large DB2 z/OS tables. The choice between the two methods depends on the specific use case and the requirements of the application. Both methods require a good understanding of the data and the access patterns, and both require monitoring and testing to ensure that the desired performance is achieved.