Rachelint commented on code in PR #15591: URL: https://github.com/apache/datafusion/pull/15591#discussion_r3084020685
########## datafusion/functions-aggregate-common/src/aggregate/groups_accumulator/blocks.rs: ########## @@ -0,0 +1,308 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Aggregation intermediate results blocks in blocked approach + +use std::{ + collections::VecDeque, + fmt::Debug, + iter, + ops::{Index, IndexMut}, +}; + +use datafusion_expr_common::groups_accumulator::EmitTo; + +/// Structure used to store aggregation intermediate results in `blocked approach` +/// +/// Aggregation intermediate results will be stored as multiple [`Block`]s +/// (simply you can think a [`Block`] as a `Vec`). And `Blocks` is the structure +/// to represent such multiple [`Block`]s. +/// +/// More details about `blocked approach` can see in: [`GroupsAccumulator::supports_blocked_groups`]. +/// +/// [`GroupsAccumulator::supports_blocked_groups`]: datafusion_expr_common::groups_accumulator::GroupsAccumulator::supports_blocked_groups +/// +#[derive(Debug)] +pub struct Blocks<B: Block> { + inner: VecDeque<B>, Review Comment: Yes, it is better to use `Vec<T>` and I tried it when I still see it a performance improvement feature. However, after many tries, I found it actually can't help dafafusion run faster (it is only something can help to better memory management)... And I finally switch to use `VecDeque` for simplicity... The experiments can be saw in this archived branch: https://github.com/Rachelint/arrow-datafusion/compare/intermeidate-result-blocked-approach-bak -- 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]
