Logical type
A logical type is a semantic type representing truth-valued data, such as true, false, or missing values, regardless of its physical representation.
DuckDB in Action
A logical type is semantic type information attached to a physical storage representation to specify how readers should interpret values.
- How it is used
- Uses semantic annotations during CSV-to-Parquet conversion so readers interpret stored values correctly.
- How deep it goes
- Explains annotations, demonstrates date conversion, and inspects Parquet metadata without developing logical-type internals beyond schemas.
- Examples
- Demonstrates encoded ranking dates, DuckDB strptime conversion, DATE output, and parquet_schema inspection.
- What you can do after
- Apply logical types with DuckDB by parsing encoded dates and verifying their Parquet schema metadata.
Statistics Slam Dunk
A logical data type represents Boolean values such as TRUE, FALSE, and missing values in R.
- How it is used
- Represents NBA quarter and game outcomes as Boolean conditions that can be grouped, counted, and reshaped.
- How deep it goes
- Explains TRUE/FALSE inspection and conversion to 0/1, then applies the values in counting and reshaping operations.
- Examples
- Uses quarter-winning conditions, six-letter result codes, and a summary table of halftime-tied NBA games.
- What you can do after
- Apply logical columns in R to create indicators, count result combinations, and reshape Boolean results into a long table.
Related concepts
- as.numeric() functionused by · The as.numeric() function in R converts a compatible object into numeric values.
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