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https://issues.apache.org/jira/browse/BEAM-7577?focusedWorklogId=280363&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-280363
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ASF GitHub Bot logged work on BEAM-7577:
----------------------------------------
Author: ASF GitHub Bot
Created on: 22/Jul/19 12:30
Start Date: 22/Jul/19 12:30
Worklog Time Spent: 10m
Work Description: EDjur commented on issue #8950: [BEAM-7577] Allow
ValueProviders in Datastore Query filters
URL: https://github.com/apache/beam/pull/8950#issuecomment-508107035
I've noticed that a small change might be needed in `datastoreio.py` or
alternatively in `query_splitter.py` in order to use this together with
ReadFromDatastore. Specifically, the `validate_split` function in
`query_splitter.py` is causing issues when using value providers as a filter:
```
for filter in query.filters:
if filter[1] in ['<', '<=', '>', '>=']:
raise SplitNotPossibleError('Query cannot have any inequality
filters.')
```
Since this function is run before the query is converted to a client_query
by calling the `_to_client_query` method, filter here will be of type
ValueProvider, which does not support indexing, therefore raising a TypeError.
I'm thinking that we should perhaps evaluate the values of our
ValueProvider-filter before calculating the split. But this means we cannot
evaluate in `_to_client_query`, which I thought was a neat solution that wasn't
particularly hacky.
For context, the flow is essentially the `expand` method in
ReadFromDatastore that calls the SplitQuery before Read, and Read is what
causes the `_to_client_query` method to be called.
Question is basically where the best place is to evaluate these filters.
@udim What's your take on this?
Edit: Will explore this again after fixing the other issue first.
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Issue Time Tracking
-------------------
Worklog Id: (was: 280363)
Time Spent: 4h 20m (was: 4h 10m)
> Allow the use of ValueProviders in
> datastore.v1new.datastoreio.ReadFromDatastore query
> --------------------------------------------------------------------------------------
>
> Key: BEAM-7577
> URL: https://issues.apache.org/jira/browse/BEAM-7577
> Project: Beam
> Issue Type: New Feature
> Components: io-python-gcp
> Affects Versions: 2.13.0
> Reporter: EDjur
> Assignee: EDjur
> Priority: Minor
> Time Spent: 4h 20m
> Remaining Estimate: 0h
>
> The current implementation of ReadFromDatastore does not support specifying
> the query parameter at runtime. This could potentially be fixed through the
> usage of a ValueProvider to specify and build the Datastore query.
> Allowing specifying the query at runtime makes it easier to use dynamic
> queries in Dataflow templates. Currently, there is no way to have a Dataflow
> template that includes a dynamic query (such as filtering by a timestamp or
> similar).
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