These parameters control mechanisms used by PPM during data import.
Key |
Description |
---|---|
READ_RATE_EPC |
To limit the main memory requirement necessary for structural information, PPM import packages the fragment files. These packages are processed in individual runs of the import component. The value stated corresponds to the package size. By increasing the value, the overhead that is generated by the individual processing of the components (for example, multiple calculation of individual instances) can be reduced. However, it is important that enough main memory is available for PPM import to store the larger volume of structural information. If required, the JVM parameters of the PPM import need to be adjusted for these clients in CTK. |
XML_IMPORT_COMMIT_RATE |
Number of fragments that are written to the database in one transaction by the XML import. |
EPC_IMPORT_COMMIT_RATE |
Number of fragments processed in the "EPC import" phase during PPM import in one transaction from the database. |
XML_IMPORT_WRITE_BUFFER |
During XML import, the fragments are saved permanently in the database by a simultaneously running background process. To balance speed fluctuations of the import or RDBMS, a buffer is used. The parameter controls the maximum number of fragments that are cached in this buffer. If the bugger size is reduced to 0, the background process is deactivated. Default value: 75 |
KI_EPC_FUNCTION_COUNT _THRESHOLD |
This parameter is used when handling large EPCs. It specifies the maximum number of functions based on which a process instance is considered to be "of normal size". Details about this mechanism are described in the PPM Data import manual. Default value: 500 |
PPM premerge mechanism
Premerges (XML and EPC) combine individually imported fragments in a runtime-based cache before saving them permanently in the database. This significantly reduces the number of database objects and increases the efficiency of the import and subsequent phases.
The effectiveness of the premerge is considerably influenced by the order of system events within the input files. If possible, associated events, such as events with identical process keys, should follow each other as closely as possible in the input files.
PPM uses the XML premerge as a default. It is used during the XML import. It processes the fragments at the earliest point in time possible.
The EPC premerge is deactivated by default. It can be used if during XML import many small individual imports run so that a combination of fragments by the XML premerge is impossible.
An increase of the premerge cache can be used to increase the area in which associated fragments are identified. Please note that this leads to increased memory requirements of the XML or PPM import. If required, the JVM parameters of the these components need to be adjusted for these clients in CTK.
Since the runtime cache is emptied when a database transaction is terminated, the transaction fragment <XML/EPC>_IMPORT_COMMIT_RATE (see above) should be adjusted if th premerge cache is significantly increased.
Key |
Description |
---|---|
XML_IMPORT_PREMERGER_CACHE_SIZE |
Size of XML premerge cache. |
EPC_IMPORT_PREMERGER_CACHE_SIZE |
Size of EPC premerge cache. |
If you specify the value 0 for the cache size, the corresponding cache is disabled.
The premerge settings apply to the XML import (runxmlimport) or PPM import (runppmimport).