Free Data Modeling Tools

Here is list of Free Data Modeling Tools that I use

• ER Win
• Oracle: SQL Developer Data Modeler 
• SQL Power Architect - Community Version

C# misc note-taking

========================Reactive Extensions=====================

The Reactive Extensions (Rx)...

• reactive extensions
• Rx = Observables + LINQ + Schedulers..

========================Digest=====================

MultiThread

1. Asynchronous Programming with Async and Await
1. Control Flow in Async Programs
1. Async Sample: Control Flow in Async.
2. what is thread context
1. Atomicity, volatility and immutability are different, part three.

Entity Framework

1. Entity Framework Tutorial.

=============== Parallel LINQ from "C# in Depth" chap 12 ================

Mandelbrot generator time with different Linq implementation

0 SingleThreadedGenerator  5697 ms - Good Pic
            var query = from row in Enumerable.Range(0, Height)
                        from column in Enumerable.Range(0, Width)
                        select ComputeIndex(row, column);

1 UnorderedRowsParallelGenerator  1410 ms - bad Pic
            var query = from row in Enumerable.Range(0, Height).AsParallel()
                        from column in Enumerable.Range(0, Width)
                        select ComputeIndex(row, column);

2 OrderedRowsParallelGenerator 1452 ms - Good Pic
            var query = from row in Enumerable.Range(0, Height)
                                              .AsParallel()
                                              .AsOrdered()
                        from column in Enumerable.Range(0, Width)
                        select ComputeIndex(row, column);

3. OrderedParallelRangeGenerator 2130 ms - Good Pic
            var query = from row in ParallelEnumerable.Range(0, Height).AsOrdered()
                        from column in Enumerable.Range(0, Width)
                        select ComputeIndex(row, column);

4. OrderedPixelsParallelGenerator      1522 ms - Good Pic
            var pixels = from row in Enumerable.Range(0, Height)
                         from column in Enumerable.Range(0, Width)
                         select new { row, column };
            var query = from pixel in pixels.AsParallel().AsOrdered()
                        select ComputeIndex(pixel.row, pixel.column);

5. UnorderedParallelRangeGenerator  2064 ms - Good Pic
            var query = from row in ParallelEnumerable.Range(0, Height)
                        from column in Enumerable.Range(0, Width)
                        select ComputeIndex(row, column)

6. UnorderedPixelsParallelGenerator 1620 ms- bad Pic
            var pixels = from row in Enumerable.Range(0, Height)
                         from column in Enumerable.Range(0, Width)
                         select new { row, column };
            var query = from pixel in pixels.AsParallel()
                        select ComputeIndex(pixel.row, pixel.column);