tobixdev opened a new issue, #14010: URL: https://github.com/apache/datafusion/issues/14010
### Describe the bug Trying to insert into a MemTable with zero partitions causes and index out of bounds error when executing. Backtrace: ``` index out of bounds: the len is 0 but the index is 0 thread 'datasource::memory::tests::test_insert_into_zero_partition' panicked at datafusion/core/src/datasource/memory.rs:373:24: index out of bounds: the len is 0 but the index is 0 stack backtrace: 0: rust_begin_unwind at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/std/src/panicking.rs:665:5 1: core::panicking::panic_fmt at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/core/src/panicking.rs:74:14 2: core::panicking::panic_bounds_check at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/core/src/panicking.rs:276:5 3: <usize as core::slice::index::SliceIndex<[T]>>::index_mut at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/core/src/slice/index.rs:307:14 4: core::slice::index::<impl core::ops::index::IndexMut<I> for [T]>::index_mut at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/core/src/slice/index.rs:28:9 5: <alloc::vec::Vec<T,A> as core::ops::index::IndexMut<I>>::index_mut at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/alloc/src/vec/mod.rs:2924:9 6: <datafusion::datasource::memory::MemSink as datafusion_physical_plan::insert::DataSink>::write_all::{{closure}} ``` ### To Reproduce The following test case produces said error: ``` // Test inserting a batch into a MemTable without any partitions #[tokio::test] async fn test_insert_into_zero_partition() -> Result<()> { // Create a new schema with one field called "a" of type Int32 let schema = Arc::new(Schema::new(vec![Field::new("a", DataType::Int32, false)])); // Create a new batch of data to insert into the table let batch = RecordBatch::try_new( schema.clone(), vec![Arc::new(Int32Array::from(vec![1, 2, 3]))], )?; // Run the experiment and expect an error let experiment_result = experiment(schema, vec![], vec![vec![batch.clone()]]) .await .unwrap_err(); // Ensure that there is a descriptive error message assert_eq!( "Error during planning: Cannot insert into MemTable with zero partitions.", experiment_result.strip_backtrace() ); Ok(()) } ``` ### Expected behavior I think there are multiple ways to address this. 1. An error during planning with a descriptive message. 2. An error during execution with a descriptive message. 3. Automatically create a single partition during insertion 4. Do not allow creating MemTables without any partitions From my point of view, 1. is the preferred solution because this allows creating "Empty MemTables that cannot become non-empty". However, I am not really familiar with the code base so opinions may vary. ### Additional context _No response_ -- 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: github-unsubscr...@datafusion.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org