alamb commented on code in PR #14699: URL: https://github.com/apache/datafusion/pull/14699#discussion_r1966501158
########## datafusion/expr-common/src/statistics.rs: ########## @@ -0,0 +1,1610 @@ +// 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. + +use std::f64::consts::LN_2; + +use crate::interval_arithmetic::{apply_operator, Interval}; +use crate::operator::Operator; +use crate::type_coercion::binary::binary_numeric_coercion; + +use arrow::array::ArrowNativeTypeOp; +use arrow::datatypes::DataType; +use datafusion_common::rounding::alter_fp_rounding_mode; +use datafusion_common::{internal_err, not_impl_err, Result, ScalarValue}; + +/// New, enhanced `Statistics` definition, represents five core statistical Review Comment: What I would love to support is a "bring your own statistics / cost model" approach -- where following DataFusion's other features, it 1. includes a solid, though basic implementation of statistics (e.g. min/max and maybe distinct value counts) 2. has APIs that help people implement fancier statistics / models if they wanted Some fancier models I imagine people would do are: 1. Histograms (this is likely the first thing people would do) 2. Multi-column sketches / samples / fancier research stuff So basically my ideal outcome would be if we knew how `StatisticsV2` would allow such a thing to be implemented, and I think that will require a trait in some form. It could end up being another variant of `StatisticsV2`, like `StatisticsV2::User` or something (like we did for LogicalPlan) -- 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 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
