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Ryan Boyd
@ryan-1
Select a sample of rows from a table
DuckDB allows sampling of data in your tables using a several different statistical techniques, usually to increase performance. The default sampling method is used in this case- this is a bernoulli variant where each vector has a specified chance of being included in the result set.
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-- uses system sampling to select 10% of the people rows SELECT * FROM people USING SAMPLE 10%;Copy code
Ryan Boyd
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Select all columns except a few
Editor's note: tired of copying/pasting many column names to select all columns except a handful? The EXCLUDE() function allows you to exclude specific columns from the result set. Together with COLUMNS() and REPLACE() it provides an easy way to specific the data you want returned.
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SELECT * EXCLUDE (column1, colum2) FROM ducks;Copy code
Ryan Boyd
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Download CSV and convert to ParquetSQL
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COPY (SELECT * FROM read_csv_auto( 'http://raw.githubusercontent.com/fivethirtyeight/data/master/bechdel/movies.csv')) TO 'movies.parquet' (FORMAT 'parquet');Copy code
Ryan Boyd
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