---
task: Load item history from CSV (ithloahis) and read history back (dssqld)
version: R1.03
source: IM 36K10J10-01EN §2.9.2; IM 36K10L50-01EN §3.6; practiced with CI-Eng-Sample 2026-09-30
status: verified
---

# Load item history (ithloahis) and read it back

**Writes to the history database.** Needs CI Server running and the items linked to an
item storage group of type *Event/Item* or *Event/Event*. The sample project provides
`CIENG_EVENT` with `CI-Eng-Sample.TANK1.LEVEL` and `.INFLOW`.

## Before loading

- A **new** storage group stores nothing until CI Server has been restarted (stop, then start
  the CI Service). Restart after creating a group.
- Only samples dated **after the start of the current storage unit** were stored; older ones
  were silently skipped (see `knowledge/issues.md` ISS-006). A restart starts a new unit.

## Input files

Event file: one sample per line.

```
EVENT
<time>,<item>,<value>
1790739700,CI-Eng-Sample.TANK1.LEVEL,47
```

Scan file: several items per line (max 100), one line per timestamp.

```
SCAN,CI-Eng-Sample.TANK1.LEVEL,CI-Eng-Sample.TANK1.INFLOW
1790739715,61,101
1790739720,62,102
```

Time is seconds since 1970 (UTC), optionally with a fraction, or a date text such as
`29-Apr-14 11:48:17.452`. Quotes and spaces around fields are optional. A blank value in a
scan line is skipped.

## Load

```
ithloahis -f <file>.csv -v
```

- `-v` shows progress (`Handle event based table`, `item … on column n`).
- `-t GMT|LST|LCT` sets how text times are read (default GMT).
- `-s <section>` puts a section in front of every item name.
- `-i` also updates the item's current value (can raise alarms and trigger objects; loads the
  system). Without it, only history is written.

## Read history back

`ITEM_HISTORY` is not exported by default; use a filter file that names the item **and** a
time range, otherwise nothing is returned:

```
@SELECT
'ITEM_NAME = "CI-Eng-Sample.TANK1.LEVEL" and SAMPLE_TIME > "30-09-2026 00:00:00" and SAMPLE_TIME < "01-10-2026 00:00:00"'
@ITEM_HISTORY
```

```
dssqld -e history.qli <filter>.qli -c -l history.qlo
```

Result columns include `NAME` (`<group>:<item>/<time>/Value`), `SAMPLE_TIME`, `ITEM_VALUE`,
`QUALITY`. Values written live (e.g. with `itmval -p`) and the value at CI Server start also
appear.

## Verified (CI-Eng-Sample, 2026-09-30)

SCAN load of LEVEL 61–63 / INFLOW 101–103 and EVENT load of LEVEL 47, 48 were all read back
with the filter above.