Poll updates from Materialized View

[caueteixeira]

Hi,

I am implementing a process to calculate the number of products a client add to their inventory in real time. I have a base query that polls the results from a materialized view every x seconds and I want it to return only the updates between two different polls and not the full set every poll. I am aware of the live view, however I don't want to use experimental features in production.

Simple representation of my current set-up:

Source Table:

CREATE TABLE order
(
client_id UInt64,
product_id UInt32,
quantity Float64,
transaction_time DateTime
)
ENGINE = MergeTree
PARTITION BY toYYYYMMDD(transaction_time)
ORDER BY (transaction_time, client_id, product_id)

Target Table:

CREATE TABLE order_agg
(
client_id UInt64,
product_id UInt32,
total_quantity SimpleAggregateFunction(sum, Float64)
)
ENGINE=AggregatingMergeTree()
PARTITION BY tuple()
ORDER BY (client_id, product_id)

Materialized View:

CREATE MATERIALIZED VIEW order_mv
TO order_agg
AS
SELECT
client_id,
product_id,
sum(quantity) as total_quantity
FROM
order
GROUP BY
client_id,
product_id

Polling Query:

SELECT
client_id,
product_id,
sum(total_quantity) AS final_quantity
FROM
order_mv
GROUP BY
client_id,
product_id

Is it possible to configure the polling query so it just return the new updates every poll?
Thanks,

Caue