Retrieving bucketting value in WITH statement for subsequent SELECT - presto

Question

I have several tables with bucketing applied. It can work great when I specify the bucket/partition parameter upfront in my SELECT query, however when I retrieve the bucket value I need from a different table - within a WITH select statement, Hive/Athena seems to no longer use the optimisation, and searches the entire database instead. I would like to learn if there is a way to write my query properly to maintain the optimisation.
For a simple example, I have two tables:
Table1
category | categoryid
---------+-----------
mass | 1
Table2
categoryid | index | value
-----------+-------+------
1 | 0 | 15
1 | 1 | 10
1 | 2 | 7
The bucketed/clustered column is categoryid. I have a single category ('mass') and would like to retrieve the value's that correspond with the category I have. So I have designed my SELECT like this:
WITH dataset AS (
SELECT categoryid
FROM Table1
WHERE category='mass'
)
SELECT index,value
FROM Table2, dataset
WHERE Table2.categoryid=dataset.categoryid
This will run, but will search the entire database it seems, because Hive doesn't know the categoryid for bucketing before commencing the search? If I swap out the final Table2.categoryid=dataset.categoryid for Table2.categoryid=1 then it will search only the fraction of the db.
So is there some way of writing this query to ensure Hive doesn't search more buckets in the second table than it has to?

Answer 1

Athena is based on Presto. Unless there is some modification in Athena in this area (and I think there currently isn't), this cannot be made to work in single query.
Recommended workaround: issue one query to gather dataset.categoryid values. Pass them as constant to your main query:
WITH dataset AS (
SELECT category
FROM Table1
WHERE category='mass'
)
SELECT index,value
FROM Table2, dataset
WHERE Table2.categoryid = dataset.categoryid
AND Table2.categoryid IN ( <all possible values> );
This is going to be improved with the additional of Dynamic Filtering in Presto, that the Presto Community is working on currently.