Incremental aggregation is
the process of capturing the changes in the source and calculating the
aggregations in a session. this process makes the integration service to update
the target incrementally and avoids the process of calculating the aggregations
on the entire source.
When the session runs with
incremental aggregation enabled for the first time on March 1, you use the
entire source. this allows the integration service to read and store the
necessary aggregate data. on march 2, when you run the session again, you
filter out all the records except those time-stamped march 2. the integration
service then processes the new data and updates the target accordingly.
(i) the first time you run an incremental aggregation session, the integration
service processes the entire source. at the end of the session, the integration
service stores aggregate data from that session run in two files, the index
file and the data file. the integration service creates the files in the cache
directory specified in the aggregator transformation properties.
(ii) each subsequent time
you run the session with incremental aggregation, you use the incremental
source changes in the session. for each input record, the integration service
checks historical information in the index file for a corresponding group. if
it finds a corresponding group, the integration service performs the aggregate
operation incrementally, using the aggregate data for that group, and saves the
incremental change. if it does not find a corresponding group, the integration
service creates a new group and saves the record data.
(iii)when writing to the
target, the integration service applies the changes to the existing target. it
saves modified aggregate data in the index and data files to be used as
historical data the next time you run the session.
(iv) if the source changes
significantly and you want the integration service to continue saving aggregate
data for future incremental changes, configure the integration service to
overwrite existing aggregate data with new aggregate data.
thanks
ur's hari
Incremental aggregation is
the process of capturing the changes in the source and calculating the
aggregations in a session. this process makes the integration service to update
the target incrementally and avoids the process of calculating the aggregations
on the entire source.
When the session runs with
incremental aggregation enabled for the first time on March 1, you use the
entire source. this allows the integration service to read and store the
necessary aggregate data. on march 2, when you run the session again, you
filter out all the records except those time-stamped march 2. the integration
service then processes the new data and updates the target accordingly.
(i) the first time you run an incremental aggregation session, the integration service processes the entire source. at the end of the session, the integration service stores aggregate data from that session run in two files, the index file and the data file. the integration service creates the files in the cache directory specified in the aggregator transformation properties.
(i) the first time you run an incremental aggregation session, the integration service processes the entire source. at the end of the session, the integration service stores aggregate data from that session run in two files, the index file and the data file. the integration service creates the files in the cache directory specified in the aggregator transformation properties.
(ii) each subsequent time
you run the session with incremental aggregation, you use the incremental
source changes in the session. for each input record, the integration service
checks historical information in the index file for a corresponding group. if
it finds a corresponding group, the integration service performs the aggregate
operation incrementally, using the aggregate data for that group, and saves the
incremental change. if it does not find a corresponding group, the integration
service creates a new group and saves the record data.
(iii)when writing to the target, the integration service applies the changes to the existing target. it saves modified aggregate data in the index and data files to be used as historical data the next time you run the session.
(iii)when writing to the target, the integration service applies the changes to the existing target. it saves modified aggregate data in the index and data files to be used as historical data the next time you run the session.
(iv) if the source changes
significantly and you want the integration service to continue saving aggregate
data for future incremental changes, configure the integration service to
overwrite existing aggregate data with new aggregate data.
thanks
ur's hari
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