Uploading Snapshots to the AWR Warehouse

Upload of AWR snapshot data from source databases occurs as an ETL process, which is a series of jobs that perform ETL—Extract, Transfer, Load—processing.

Extract AWR Data

As part of the collection process, a DBMS job runs at regular intervals to collect AWR snapshots and create dumps in a staging area on the target host. Initially, this job collects existing AWR data and subsequently collects the latest snapshot in incremental fashion. If there is too much data to collect initially, the job staggers the collection process to avoid placing a burden on the source database.

Transfer AWR Data

An Enterprise Manager job runs at regular intervals on the respective host to transfer the source database AWR data to a staging area on the warehouse host for further processing. This job copies the dump files using an agent-to-agent file transfer mechanism. Upon successful upload to the warehouse, the dump file is removed from the host staging area.

Loading Transferred Data into the AWR Warehouse

A DBMS job runs at regular intervals to process multiple source database dump files and import them into the warehouse schema. This occurs incrementally to ensure snapshots were not already imported. As part of the import process, the job maps DB IDs to ensure uniqueness. This information is maintained in a separate table to handle duplicate DB IDs and to support multitenant scenarios; for example, multiple customers' data stored in a single AWR database, where there might be duplicate database names. AWR data remains in the warehouse up to the configurable retention period, after which it is purged.

Note:

You can also upload snapshots on-demand. Select a source database on the dashboard and then select Upload Snapshots Now from the Actions menu.