Lucene.NET SQL is a library that enables persistance of Lucene index files to SQL databases.

• MySQL
• PostgreSQL
• SQL Server

Currently this package is in alpha while we wait for lucene.net 4.8 to be released.

If you want to use Lucene.NET SQL to develop commercial projects, and applications, the Commercial license is the appropriate license. With this option, your source code is kept proprietary. Purchase a Lucene.NET SQL Commercial License at gowengit.github.io/lucene-net-sql

If you are creating an open source application under a license compatible with the GNU GPL license v3, you may use Lucene.NET SQL under the terms of the GPLv3.

Below are some general use examples of the library.

var options = new SqlDirectoryOptions(connectionString, "ExampleDirectory");

using var mySqlOperator = MySqlLuceneOperator.Create(options);

using var directory = new LuceneSqlDirectory(options, mySqlOperator);

// Rest is standard Lucene code

using var analyzer = new StandardAnalyzer(LuceneVersion.LUCENE_48);

using var writer = new IndexWriter(directory, new IndexWriterConfig(LuceneVersion.LUCENE_48, analyzer));

// ...

Note: MySqlLuceneOperator is linked to a single MySQL connection so should be either transient or short lived.

Performance benchmarks were done to compare local file system vs local SQL instance performance.

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19041.508 (2004/?/20H1)
AMD Ryzen 5 2600, 1 CPU, 12 logical and 6 physical cores
.NET Core SDK=3.1.401
  [Host]     : .NET Core 3.1.7 (CoreCLR 4.700.20.36602, CoreFX 4.700.20.37001), X64 RyuJIT
  Job-QKPTDT : .NET Core 3.1.7 (CoreCLR 4.700.20.36602, CoreFX 4.700.20.37001), X64 RyuJIT