SAP Knowledge Base Article - Public

3634879 - Temporary tables are not being deleted automatically in SAP Datasphere

Symptom

Temporary tables with the prefix DT__ are not being deleted automatically after the execution of Data Flows in SAP Datasphere.
These tables may consume significant disk and memory resources in the Datasphere HANA instance.

Environment

SAP Datasphere - Data Flow

Reproducing the Issue

  1. In Space Management, click on "Monitor"
  2. On the Monitor page, under "Table Details" tables with the prefix DT__ are visible, consuming disk and memory resources, even though the associated Data Flow has already completed or failed. 

Cause

Temporary tables with the prefix DT__ are internal objects created automatically during the execution of Data Flows in SAP Datasphere. Under normal completion, they are removed on job exit. If a Data Flow terminates abnormally (for example, manual cancellation or a job crash), the table may be left behind in the customer HANA schema.

Resolution

SAP Datasphere Data Flow now performs an automatic cleanup of leftover DT__ tables. The default configuration is:
  • Schedule: every Sunday at 03:00 (timezone of the internal HANA instance, typically UTC).
  • Minimum table age: only DT__ tables older than 7 days are dropped.
This behavior is now enabled automatically starting with Data Integration Runtime Version 2613 (see in About - More). No customer action is required.
 
Both the schedule and the minimum table age are configurable per tenant. If the defaults do not fit the workload, open a customer case in SAP for Me, selecting Data Flow as the product function (component DS-DI-DF) and specifying:
  1. The desired cleanup schedule (cron expression, HANA Scheduler syntax), and/or
  2. The desired minimum table age in days.
In case of any unexpected issues, please open a customer case for the same component.

Keywords

temporary tables, DT table, DT__, orphaned, internal tables, shadow tables, cleanup, Data Flow, automatic deletion , KBA , EIM-DS-DI , DI, DWC, Data Suite usage of DS-Lite , DS-SM , Space Management , DS-DI-DF , Data Flow Runtime , Problem

Product

SAP Datasphere all versions