Read the Top N Rows from Large Text Files with C#

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This post describes one way that you can read the top N rows from large text files with C#. This is very useful when working with giant files that are too big to open, but you need to view a portion of them to determine the schema, data types, etc. I’ve used PowerShell many times to do this with large csv files, but in this example we’re going to use C# and look at the Wikipedia XML dump of pages and articles. The 3017-03-01 dump is very large and comes in at 59.5 GB. The script is short and simple. All it does is readRead More →

Select columns from multiple CSV files

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I recently encountered a scenario where I needed to use PowerShell to select columns from CSV files and output the results to a new set of files. This was necessary because an additional column was accidentally introduced to CSV files that were being loaded hourly with SSIS. When the additional column appeared, SSIS began to choke on the files, resulting in package failures. The hourly process actually continued working, but a couple dozen CSV source files needed to be modified before they could be loaded into the data warehouse. The diagram above shows the required modification. PowerShell to the Rescue PowerShell is my favorite Business Intelligence tool that isRead More →