aucahuasi commented on code in PR #14226: URL: https://github.com/apache/arrow/pull/14226#discussion_r996432256
########## cpp/src/parquet/arrow/reader.cc: ########## @@ -1107,8 +1112,13 @@ class RowGroupGenerator { if (!reader->properties().pre_buffer()) { row_group_read = SubmitRead(cpu_executor_, reader, row_group, column_indices); } else { + reader->parquet_reader()->PreBuffer({row_group}, column_indices_, + reader_properties_.io_context(), + reader_properties_.cache_options()); auto ready = reader->parquet_reader()->WhenBuffered({row_group}, column_indices); if (cpu_executor_) ready = cpu_executor_->TransferAlways(ready); + // wait for buffering the rowgroup before read it + ready.Wait(); Review Comment: It seems -somehow- the next rowgroup triggers `ReadOneRowGroup` and it starts reading, but the cache entries are empty (because it didn't call `PreBuffer` before) I did a simple change: when we don't transfer the future using `if (cpu_executor_) ready = cpu_executor_->TransferAlways(ready);` it works without wait. -- 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...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org