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sheetreader
Downloads 7.9kthis week
GitHub stars 59
Extension descriptor (YAML)

Fast, parallel Excel (XLSX) loading with low memory overhead.

Maintainer(s): harrygav, freddie-freeloader

Compatibility Matrix

This table covers all DuckDB releases that have not reached end-of-life, including LTS releases, and shows the 2 most recent patch releases of each. Older patch releases are not listed, but the extension may be available for them as well.

Platform 1.4.4 1.4.5 1.5.5 1.5.6 2.0.0
Linux AMD64
Linux ARM64
macOS AMD64
macOS ARM64
Windows AMD64
Windows ARM64
WebAssembly

Installing and Loading 

INSTALL sheetreader FROM community;
LOAD sheetreader;

Example 

-- Install and load the extension
INSTALL sheetreader FROM community; LOAD sheetreader;

-- Read an Excel spreadsheet
SELECT * FROM sheetreader('data.xlsx');

-- Read a specific worksheet
SELECT * FROM sheetreader('data.xlsx', sheet_name = 'Sales');

-- Load a spreadsheet in parallel into a table
CREATE TABLE data AS
FROM sheetreader('data.xlsx', threads = 8);

About sheetreader

SheetReader enables fast, memory-efficient loading of Excel (XLSX) spreadsheets through specialized parsing routines and parallel processing. Unlike conventional XML-based Excel parsers, it is optimized for spreadsheet data, improving runtime and memory efficiency especially for large spreadsheets, as shown in our research paper and recent benchmarks.

Available Parameters

Parameter Description Type Default
sheet_index Index of the worksheet to read (starting at 1). Cannot be combined with sheet_name. INTEGER 1
sheet_name Name of the worksheet to read. Cannot be combined with sheet_index. VARCHAR ""
threads Number of threads used for parallel parsing. INTEGER Half of available cores (minimum 1)
skip_rows Number of rows to skip before reading. INTEGER 0
has_header Require the first row to be usable as column headers. When false, SheetReader still attempts to use the first row as headers but does not fail if it cannot. BOOLEAN false
types Column types (VARCHAR, BOOLEAN, DOUBLE, DATE), one per column. LIST(VARCHAR) Inferred from the first two rows after skipped rows
coerce_to_string Coerce cells in VARCHAR columns to strings. BOOLEAN false
force_types Enforce specified types even if they conflict with inferred types; incompatible cells become NULL or are converted to strings when coerce_to_string is set. BOOLEAN false

Background

SheetReader was developed as part of the PolyDB research project. Our research introduced a spreadsheet-specialized parser designed for use across multiple systems, including integrations for PostgreSQL, Python/pandas, R data frames, and DuckDB (see the SheetReader core repository).

If SheetReader was helpful in your research, please consider citing our paper:

@article{GavriilidisHZM23,
  author  = {Haralampos Gavriilidis and Felix Henze and Eleni Tzirita Zacharatou and Volker Markl},
  title   = {SheetReader: Efficient Specialized Spreadsheet Parsing},
  journal = {Information Systems},
  volume  = {115},
  pages   = {102183},
  year    = {2023},
  doi     = {10.1016/j.is.2023.102183}
}

Added Functions

function_name function_type description comment examples
sheetreader table NULL NULL  

Overloaded Functions

This extension does not add any function overloads.

Added Types

This extension does not add any types.

Added Settings

name description input_type scope aliases typed_value
temp_directory Set the directory to which temporary files are written. VARCHAR GLOBAL [] post.db.tmp