| commit | 186732d6912a5348ff2fc1cc048c6a34decdb961 | [log] [tgz] |
|---|---|---|
| author | Gabriel Reid <gabrielr@ngdata.com> | Wed Feb 05 13:14:20 2014 +0100 |
| committer | Gabriel Reid <gabrielr@ngdata.com> | Wed Feb 05 13:14:20 2014 +0100 |
| tree | 62e4c1e7ab91a859bc19e576882f4e0eaa0bac72 | |
| parent | 9f752e860bf783919da0ace93174be79c2180fee [diff] |
Return a single object for single-col enumerator Optiq expects that an enumerator of a single column returns the single value of that column, and not an array with length 1. The CsvEnumerator is changed to be generically typed as Object instead of Object[], and return a single object when only a single column is being read.
Optiq adapter that reads CSV files.
Optiq-csv is a nice simple example of how to connect Optiq to your own data source and quickly get a full SQL/JDBC interface.
You need Java (1.6 or higher; 1.7 preferred), git and maven (3.0.4 or later).
$ git clone git://github.com/julianhyde/optiq-csv.git $ cd optiq-csv $ mvn compile
Let‘s take a quick look at optiq-csv’s (and optiq‘s) features. We’ll use sqlline, a SQL shell that connects to any JDBC data source and is included with optiq-csv.
Connect to Optiq and try out some queries:
$ ./sqlline sqlline> !connect jdbc:optiq:model=target/test-classes/model.json admin admin sqlline> !tables sqlline> !describe emps sqlline> SELECT * FROM emps; sqlline> EXPLAIN PLAN FOR SELECT * FROM emps; sqlline> !connect jdbc:optiq:model=target/test-classes/smart.json admin admin sqlline> EXPLAIN PLAN FOR SELECT * FROM emps; sqlline> SELECT depts.name, count(*) . . . .> FROM emps JOIN depts USING (deptno) . . . .> GROUP BY depts.name; sqlline> VALUES char_length('hello, ' || 'world!'); sqlline> !quit
As you can see, Optiq has a full SQL implementation that can efficiently query any data source.
For a more leisurely walk through what Optiq can do and how it does it, try the Tutorial.