Understanding Essbase Partitioning

Understanding Essbase Partitioning

A partition is the region of a database that is shared with another database. An Essbase partitioned application can span multiple servers, processors, or computers.

Partition Types

Table 33 lists the types of partitions that are supported in Essbase:

Table 33. Partition Types

Partition Type	Description	Applies To
Replicated	A copy of a portion of the data source that is stored in the data target. See Replicated Partitions.	Block storage databases Aggregate storage databases
Transparent	Allows users to access data from the data source as though it were stored in the data target. The data is, however, stored at the data source, which can be in another application or Essbase database, or on another Essbase Server. See Transparent Partitions.	Block storage databases Aggregate storage databases
Linked	Sends users from a cell in one database to a cell in another database. Linked partitions give users a different perspective on the data. See Linked Partitions.	Block storage databases

Use the information in Table 34 to help you choose which type of partition to use:

Table 34. Features Supported by Partition Type

Feature	Replicated	Transparent	Linked
Up-to-the-minute data		x	x
Reduced network traffic	x		x
Reduced disk space		x	x
Increased calculation speed	x
Smaller databases		x	x
Improved query speed	x		x
Invisible to end users	x	x
Access to databases with different dimensionality			x
Easier to recover	x
Less synchronization required			x
Ability to query data based on its attributes		x	x
Ability to use front-end tools that are not distributed OLAP-aware	x	x
Easy to perform frequent updates and calculations		x
Ability to update data at the data target		x	x
View data in a different context			x
Perform batch updates and simple aggregations	x

Parts of a Partition

Partitions contain the following parts, as illustrated in Figure 46, Parts of a Partition and described in Table 35, Parts of a Partition.

Figure 46. Parts of a Partition

Table 35. Parts of a Partition

Part	Description
Type of partition	A flag indicating whether the partition is replicated, transparent, or linked.
Data source information	The server, application, and database name of the data source.
Data target information	The server, application, and database name of the data target.
Login and password	The login and password information for the data source and the data target. This information is used for internal requests between the two databases to execute administrative and end-user operations.
Shared areas	A definition of one or more areas, or regions, shared between the data source and the data target. To share more than one noncontiguous portion of a database, define multiple areas in a single partition. This information determines which parts of the data source and data target are shared so that Essbase can put the proper data into the data target and keep the outlines for the shared areas synchronized.
Member mapping information	A description of how the members in the data source map to members in the data target. Essbase uses this information to determine how to put data into the data target if the data target and the data source use different names for some members and dimensions.
State of the partition	Information about whether the partition is up-to-date and when the partition was last updated.

Data Sources and Data Targets

Partitioned databases contain at least one data source (the primary site of the data) and at least one data target (the secondary site of the data). One database can serve as the data source for one partition and the data target for another partition. When defining a partition, you map cells in the data source to their counterparts in the data target.

Figure 47. Data Source and Data Target

An Essbase database can contain many partitions, as well as data that is not shared with any other Essbase database. You can define partitions between the following databases:

• Different databases in different applications, as long as each database uses the same language and the same Unicode-related mode.
  The applications can be on the same computer or different computers.
• Different databases in one block storage application.
  This practice is not recommended, because the full benefits of partitioning databases are realized when each database is in a separate application.

You can define only one partition of each type between the same two databases. For example, you can create only one replicated partition between the Sampeast.East and Samppart.Company databases. The East or Company databases can, however, contain many replicated partitions that connect to other databases.

One database can serve as the data source or data target for multiple partitions. To share data among many databases, create multiple partitions, each with the same data source and a different data target, as shown in Figure 48, Data Shared at Multiple Targets:

Figure 48. Data Shared at Multiple Targets

Table 36 lists the combinations of block storage and aggregate storage databases as data target and data source that are supported by each partition type:

Table 36. Combinations of Data Targets and Data Sources Supported by Partiti