Julian Hyde created OPTIQ-410:
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Summary: Allow lattice tiles to satisfy a query by rolling up
Key: OPTIQ-410
URL: https://issues.apache.org/jira/browse/OPTIQ-410
Project: Optiq
Issue Type: Bug
Reporter: Julian Hyde
Assignee: Julian Hyde
If a lattice has a materialized tile on say columns (x, y, z), allow that tile
to be used to evaluate a query on say (x) or (y, z). Implementation would
require an extra aggregation to roll up from (x, y, z) to the actual column set
(y, z).
Measures would need to be present in the materialization, and be able to be
rolled up; for instance, count(a) is rolled up from a partial result p using
sum(p). Min, max and sum roll up using themselves.
You can also compute aggregate functions on grouping columns, for example
min(x), and expressions of aggregate functions.
Given the materialization
{code:json}
{
auto: false,
defaultMeasures: [ {
agg: 'count'
} ],
tiles: [ {
dimensions: [ 'the_year', ['t', 'quarter'] ],
measures: [ {
agg: 'sum',
args: 'unit_sales'
}, {
agg: 'sum',
args: 'store_sales'
}, {
agg: 'count'
} ]
} ]
{code}
you can satisfy the query
{code:sql}
select t."the_year",
count(*) as c,
min("quarter") as q,
sum("unit_sales") * 10 as us
from "foodmart"."sales_fact_1997" as s
join "foodmart"."time_by_day" as t using ("time_id")
group by t."the_year"
{code}
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