alamb commented on code in PR #21970: URL: https://github.com/apache/datafusion/pull/21970#discussion_r3188852249
########## benchmarks/src/bin/gen_wide_data.rs: ########## @@ -0,0 +1,347 @@ +// 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. + +//! Synthesizes parquet datasets for the `wide_schema` / `narrow_schema` +//! benchmark suites. +//! +//! The base schema has 8 columns with deterministic synthetic data: +//! +//! id Int64 monotonic primary key +//! value Float64 numeric value (~5 figures) +//! count Int64 auxiliary integer +//! ts Date32 spread across ~6 years +//! category Utf8 low-cardinality (7 values) +//! flag Utf8 low-cardinality (3 values) +//! status Utf8 low-cardinality (2 values) +//! text Utf8 ~40-char synthetic string +//! +//! `--width-factor N` replicates the schema with `_2`, `_3`, …, `_N` +//! suffix copies. The suffix-renamed copies are zero-filled arrays of +//! the same datatype, laid out **before** the base columns in the +//! output schema — so the base data columns sit at the end. This +//! makes column lookup for the filter / project columns traverse +//! past all the padding, exercising any per-column-position cost in +//! the scanner / planner. +//! +//! Zero-filled rather than null because the parquet reader can Review Comment: why not add actual values? -- 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]
