2010YOUY01 opened a new pull request, #13540: URL: https://github.com/apache/datafusion/pull/13540
## Which issue does this PR close? <!-- We generally require a GitHub issue to be filed for all bug fixes and enhancements and this helps us generate change logs for our releases. You can link an issue to this PR using the GitHub syntax. For example `Closes #123` indicates that this PR will close issue #123. --> Closes https://github.com/apache/datafusion/issues/10069 ## Rationale for this change <!-- Why are you proposing this change? If this is already explained clearly in the issue then this section is not needed. Explaining clearly why changes are proposed helps reviewers understand your changes and offer better suggestions for fixes. --> To make it easier to test memory-limited queries, i was looking for a datasource which can generate long streams, and itself doesn't consume lots of memory. There are several existing approaches are close, but can't fully satisfy this requirement: - `MemoryExec` have to buffer all output data up front - `select * from unnest(generate_series(1,10000))` also have to buffer all output during construction - It's possible to do such tests on large files, however it would be hard to setup and takes longer to run So in this PR, a new `StreamingMemoryExec` is introduced, it can be used to generate batches lazily by defining a 'iterator' on `RecordBatch` in its interface. And a new user-defined table function is implemented with this new execution plan. I also think this UDTF can be useful to tests/micro-benchmarks in general ``` > select * from generate_series(1,3); +-------+ | value | +-------+ | 1 | | 2 | | 3 | +-------+ ``` ## What changes are included in this PR? <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> 1. Move `TableFunctionImpl` from `datafusion` crate -> `datafusion-catalog` crate, so new UDTFs defined in `datafusion-functions-table` crate won't have circular dependency with `datafusion` crate (`TableFunctionImpl` depends on `TableProvider` in `datafusion-catalog` crate, so I think it's the best place to move it to) 2. Introduced `StreamingMemoryExec` 3. Implemented a new UDTF `generate_series()` ## Are these changes tested? <!-- We typically require tests for all PRs in order to: 1. Prevent the code from being accidentally broken by subsequent changes 4. Serve as another way to document the expected behavior of the code If tests are not included in your PR, please explain why (for example, are they covered by existing tests)? --> Unit tests for `StreamingMemoryExec`, and `sqllogictest`s for `generate_series()` UDTF ## Are there any user-facing changes? No <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> <!-- If there are any breaking changes to public APIs, please add the `api change` label. --> -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
