---
name: history-management
description: >-
  CI Server R1.03 HISTORY Service and item history. Use when the user wants to store item values
  in history (item storage group, storage group item, Scan/Time, Event/Item, Event/Event,
  Direct, scan interval, averaging, quality codes, priority), set rollover interval, life time
  or retention of history, use aggregation (30 minutes, hourly, shift, daily, weekly, monthly,
  yearly maximum / minimum / average / integral / standard deviation / counter / differential
  summation, ithsag.sup, completion notification), read history (ITEM_HISTORY, GROUP_NAME,
  INTERPOLATION, ATTRIBUTE), load history from CSV (ithloahis), force a rollover, check storage
  groups and units (hisdbg, his_units, history files h*.his), repair or recover history
  (hisrep, hisrecover), or archive and retrieve history (has.sup, hasman, hasdbg, tape, DVD,
  disk archive). Sources IM 36K10L20-01EN, IM 36K10C40-01EN, IM 36K10L35-01EN.
---

# History management (R1.03)

Background: `knowledge/manuals/IM36K10C40-01EN.md` (storage group fields, types, aggregation,
archive, reading history), `IM36K10L20-01EN.md` (history manager, files, `hisdbg`, utilities,
archive administration), `IM36K10L35-01EN.md` (item history processes and setup files).

Rules:
- Run `system-check` first; follow the user's chosen way of working.
- **Deleting a storage group, a unit or unknown files deletes history for good.** Life time
  changes can delete old units at the next rollover. Only with the user's approval, and never
  on production data without a backup.
- A new storage group stores nothing until CI Server is restarted (ISS-006): plan the restart
  with the user (admin).
- `has.sup` / `ithsag.sup` / `ith*.sup` changes need admin rights and a restart: hand them to
  the user (skill `portal-setup`, task `change-setup-file.md`).

| Task | File | Status |
|---|---|---|
| Create item storage groups (Event/Item, Scan/Time, Aggregation) and add items by quick load; remove them | `tasks/storage-groups.md` | verified |
| Read history with `dssqld` (`ITEM_HISTORY`, per group); aggregates | `tasks/storage-groups.md` §4 | verified |
| Load history from CSV (`ithloahis`); which time stamps are accepted | skill `system-management`, task `load-history.md` | verified |
| Check groups, units, clients, rollover with `hisdbg` | `tasks/history-checks.md` | verified |
| Archive / retrieve, `hasdbg` | C40 summary §4, L20 summary §5 | from docs (no archive device) |
| Repair and recovery (`hisrep`, `hisrecover`, `isfrename`, `hiswrn`) | L20 summary §4 | from docs |
| Reading history from classes, reports, ODBC | C40 summary §5 | from docs (phases 6, 11) |