Hierarchy
SAP_BW (Software Component) SAP Business Warehouse⤷
BW-WHM (Application Component) Warehouse Management⤷
BW_CORE_WHM_MISC (Package) BW WHM parts that are needed in the CORE
Basic Data
| Data Element | RSBLOCKSIZE |
| Short Description | Block Size for Building Aggregate |
Data Type
| Category of Dictionary Type | Direct Type Entry | |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | ||
| Data Type | INT4 | 4-byte integer, integer number with sign |
| Length | 10 | |
| Decimal Places | 0 | |
| Output Length | 11 | |
| Value Table |
Further Characteristics
| Search Help: Name | ||
| Search Help: Parameters | ||
| Parameter ID | ||
| Default Component name | ||
| Change document | ||
| No Input History | ||
| Basic direction is set to LTR | ||
| No BIDI Filtering |
Field Label
| Length | Field Label | |
| Short | 10 | Block Size |
| Medium | 15 | Block Size |
| Long | 31 | Block Size for Building Aggreg. |
| Heading | 10 | Block Size |
Documentation
Definition
System-wide parameter to determine the block size when building aggregates.
Use
If the E or F table of the source for the aggregate structure is larger than the BLOCKSIZE parameter in table RSADMINC, the source is not all read at once, but is divided into blocks. This prevents an overflow of the temporary table space PSAPTEMP. A characteristic, with a value range divided into intervals, is used to divide the source into blocks. Only data from this type of interval is read from the source and written to the aggregate.
Note the following points:
- If the block characteristic is not the partition characteristic (the request for the F table (Oracle only) and a time characteristic for the E table (Oracle, DB2/390, Informix only)), the runtime can require much longer, since all partitions must be read each time the block is read. The program first tries to use the corresponding partitioning characteristic as the block characteristic and only uses a different partitioning characteristic if not enough blocks can be built. In this case, it is very likely that the BLOCKSIZE is too small. Increase this value if possible. (This is only possible if your database supports partitioning and the InfoCube is partitioned).
- If the source is not partitioned, the program initially uses the time characteristics in the aggregate to build blocks. The system only uses other characteristics if not enough blocks can be created (for example, if the aggregate only contains 0CALYEAR). The blocks may differ greatly in size, since the data is not distributed equally (checking this would be very time-consuming). Try to choose the BLOCKSIZE so that the time characteristics can be used.
- The least optimal situation is when a characteristic that only occurs in the source not in the aggregate is used to form the blocks. Blocks with a CHANGEID not equal to 0 must be written to the F table for the aggregate and subsequently compressed. Try to avoid this by changing the parameter BLOCKSIZE.
Unfortunately, we do not have a general recommendation for the BLOCKSIZE, since there are also large differences between the various databases that SAP BW supports.
If no value is maintained for the BLOCKSIZE parameter in Customizing (activity in IMG: Parameters for Aggregates), or if the value is 0, the default value of 100,000,000 is used (exception: DB6 = 10,000,000).
Dependencies
Example
History
| Last changed by/on | SAP | 20140117 |
| SAP Release Created in | 30A |
