The function 'poisson' in the 'hana_ml.algorithms.pal.random' module draws samples from a Poisson distribution, given a database connection object, an optional average number of events in an interval, an optional number of random data to be generated, an optional seed for the random number generator, and an optional thread ratio.
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Here is a Python code template based on the provided documentation:

```python
from hana_ml import ConnectionContext
from hana_ml.algorithms.pal.random import poisson

# Create a connection
cc = ConnectionContext(address='myHanaHost', port=30015, user='myUsername', password='myPassword')

# Set parameters
theta = 1.0
num_random = 100
seed = None
thread_ratio = None

# Draw samples from a poisson distribution
res = poisson(conn_context=cc, theta=theta, num_random=num_random, seed=seed, thread_ratio=thread_ratio)

# Print the result
print(res.collect())
```

Please replace `'myHanaHost'`, `'myUsername'`, and `'myPassword'` with your actual HANA host, username, and password. You can also adjust the parameters `theta`, `num_random`, `seed`, and `thread_ratio` as needed.