Certain issues that may happen and will unfortunately require an initialization of the delta extraction. When loading data from ECC the data volume may be huge, but you will be able to extract all the data again. When it comes to BI Statistics, the volume may be as huge, but you probably will not be able to extract everything again.
I have dealt with a situation where SAP Note #1472057 needed to be applied. Consequently, as instructed by the SAP Note, an intialization was run. The problem was that, in order to gather the records that were missing, all the data from Statistics InfoCubes (0TCT_C01, 0TCT_C02 and 0TCT_C03) was deleted. As a result, when the initialization was run, it was pulling barely 1% of the data that the InfoCubes had.
The data extracted by the 0TCT_DS01, 0TCT_DS02 and 0TCT_DS03 datasources is based on statistics generated during the runtime of queries. These statistics are stored in the RSDDSTAT_OLAP table and RSDDSTAT_DM view. When extracted, the same data is stored in the PSA, InfoCube and tables. A single execution of a query generates nearly 40 records. In a live system, a lot of users would be executing their queries. At the end of each day a large number of entries has been generated in the underlying tables. If no deletion happens, imagine how many entries would be there at the end of a month!
Statistics are important but are not as critical as the ECC transactional Data. In case a certain range of data is really missing on your BI statistics it won’t be as critical as missing FI data which will not allow you to close months, periods and years, for example. The purpose of the BI statistics is actually to monitor the BW system.
You may set the frequency of deletion, with the parameter TCT_KEEP_OLAP_DM_DATA_N_DAYS (table RSADMIN). With this parameter, you will define for how many days the statistical data is going to be kept in your system. If the timestamp RSDDSTAT_DM-STARTTIME is older than that, the entry is deleted. If no value is informed on this parameter, the default value of 14 days is used.
If you are wondering how to create, update or delete this parameter, you may use the report SAP_RSADMIN_MAINTAIN. In the screenshot below, the TCT_KEEP_OLAP_DM_DATA_N_DAYS parameter is being inserted with the value 30 (days). If you don't have this parameter in RSADMIN, the defaullt value of 14 days is considered (which is also the minimum).
You should define a number that is appropriate for your loading schedule, in order to have the data you need still available for extraction if you notice mismatches or missing records on the deltas. In case you find out that something is wrong, you may even increase the paramater, to give you a longer period to understand the root-cause and fix the issue, before the data is deleted.
Contains Statistical Data.
Contains Statistical Data. View based on tables RSDDSTATHEADER, RSDDSTATINFO and RSDDSTATDM.
Defines for how long the statistical data should be kept in the RSDDSTAT_OLAP table and RSDDSTAT_DM view.
(BW 7.1 only) Deletes the old unused data from 0TCT data-targets, older than 30/182 days by default.
(BW 7.1 only) Deletes the old data from PSAs of 0TCT datastore objects, older than 14 days by default.
(BW 7.1 only) Deletes the change log entries for 0TCT datastore objects, older than 14 days by default.
(BW 7.1 only) Deletes the data from the statistical tables associated with query performance.
(BW 7.1 only) Runs reports RSTCC_ACCU, RSTCC_DELETE_PSA_OLD_DATA and RSTCC_DELETE_CHNG_LOG_DATA.
Related SAP Notes