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Do not modify or truncate critical System tables


Reported symptoms include the following problems and similar symptoms that result in production systems becoming corrupt and, therefore, unavailable:

  • Log in fails after critical pr_sys_app tables are truncated.
  • Production system not available after pr_sys_app tables are truncated.

Users report the problem after having truncated database tables, including two critical System application  tables, while some node in the cluster is still running:

  • pr_sys_app_ruleset_index
  • pr_sys_app_hierarchy_flat


Login fails

Portals are not available for several hours

Production system not available


Root cause analysis of the reported problems finds that two critical System tables were tampered with. Usually, the System tables have been truncated:



Why the tables, pr_sys_app_ruleset_index and pr_sys_app_hierarchy_flat, are important

The System tables, pr_sys_app_ruleset_index and pr_sys_app_hierarchy_flat, are crucial to the runtime features for Application-based filtering of reports and for Application-Based Assembly (ABA) rule assembly cache. These tables must be accurate for the system to operate correctly.  During each session authorization, the system ensures that these tables are correct for that user’s ruleset list and application tree.

Why you must not touch the tables, pr_sys_app_ruleset_index and pr_sys_app_hierarchy_flat

Human intervention is the leading cause of problems with these tables. If any node is running while the tables are manually truncated, then that node will continue to write rows.  As the system reads and writes rows to those tables (while the manual second step truncation is going on), it causes the tables to become corrupt. This will cause much greater harm to your system than any other problem you may be trying to diagnose.


Do not truncate or tamper with these two critical System tables:



If you truncate or touch these tables, your Pega deployment will be corrupt and lead to a Sev-1 (Production Down) scenario.


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