mirror of
https://github.com/apache/druid.git
synced 2025-03-03 07:49:13 +00:00
42590ae64b
* Refresh query docs. Larger changes: - New doc: querying/datasource.md describes the various kinds of datasources you can use, and has examples for both SQL and native. - New doc: querying/query-execution.md describes how native queries are executed at a high level. It doesn't go into the details of specific query engines or how queries run at a per-segment level. But I think it would be good to add or link that content here in the future. - Refreshed doc: querying/sql.md updated to refer to joins, reformatted a bit, added a new "Query translation" section that explains how queries are translated from SQL to native, and removed configuration details (moved to configuration/index.md). - Refreshed doc: querying/joins.md updated to refer to join datasources. Smaller changes: - Add helpful banners to the top of query documentation pages telling people whether a given page describes SQL, native, or both. - Add SQL metrics to operations/metrics.md. - Add some color and cross-links in various places. - Add native query component docs to the sidebar, and renamed them so they look nicer. - Remove Select query from the sidebar. - Fix Broker SQL configs in configuration/index.md. Remove them from querying/sql.md. - Combined querying/searchquery.md and querying/searchqueryspec.md. * Updates. * Fix numbering. * Fix glitches. * Add new words to spellcheck file. * Assorted changes. * Further adjustments. * Add missing punctuation.
57 lines
2.8 KiB
Markdown
57 lines
2.8 KiB
Markdown
---
|
|
id: sorting-orders
|
|
title: "String comparators"
|
|
---
|
|
|
|
<!--
|
|
~ 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.
|
|
-->
|
|
|
|
> Apache Druid supports two query languages: [Druid SQL](sql.md) and [native queries](querying.md).
|
|
> This document describes the native
|
|
> language. For information about functions available in SQL, refer to the
|
|
> [SQL documentation](sql.md#scalar-functions).
|
|
|
|
These sorting orders are used by the [TopNMetricSpec](./topnmetricspec.md), [SearchQuery](./searchquery.md), GroupByQuery's [LimitSpec](./limitspec.md), and [BoundFilter](./filters.html#bound-filter).
|
|
|
|
## Lexicographic
|
|
Sorts values by converting Strings to their UTF-8 byte array representations and comparing lexicographically, byte-by-byte.
|
|
|
|
## Alphanumeric
|
|
Suitable for strings with both numeric and non-numeric content, e.g.: "file12 sorts after file2"
|
|
|
|
See https://github.com/amjjd/java-alphanum for more details on how this ordering sorts values.
|
|
|
|
This ordering is not suitable for numbers with decimal points or negative numbers.
|
|
* For example, "1.3" precedes "1.15" in this ordering because "15" has more significant digits than "3".
|
|
* Negative numbers are sorted after positive numbers (because numeric characters precede the "-" in the negative numbers).
|
|
|
|
## Numeric
|
|
Sorts values as numbers, supports integers and floating point values. Negative values are supported.
|
|
|
|
This sorting order will try to parse all string values as numbers. Unparseable values are treated as nulls, and nulls precede numbers.
|
|
|
|
When comparing two unparseable values (e.g., "hello" and "world"), this ordering will sort by comparing the unparsed strings lexicographically.
|
|
|
|
## Strlen
|
|
Sorts values by the their string lengths. When there is a tie, this comparator falls back to using the String compareTo method.
|
|
|
|
## Version
|
|
Sorts values as versions, e.g.: "10.0 sorts after 9.0", "1.0.0-SNAPSHOT sorts after 1.0.0".
|
|
|
|
See https://maven.apache.org/ref/3.6.0/maven-artifact/apidocs/org/apache/maven/artifact/versioning/ComparableVersion.html for more details on how this ordering sorts values. |