ODBC to Parquet
A command line tool to query an ODBC data source and write the result into a parquet file.
- Small memory footprint. Only holds one batch at a time in memory.
- Fast. Makes efficient use of ODBC bulk reads, to lower IO overhead.
- Flexible. Query any ODBC data source you have a driver for. MySQL, MS SQL, Excel, ...
Mapping of types in queries
The tool queries the ODBC Data source for type information and maps it to parquet type as such:
| ODBC SQL Type | Parquet Type |
|---|---|
| Decimal(p < 39, s) | Decimal(p,s) |
| Numeric(p < 39, s) | Decimal(p,s) |
| Bit | Boolean |
| Double | Double |
| Real | Float |
| Float(p: 0..24) | Float |
| Float(p >= 25) | Double |
| Tiny Integer | Int8 |
| Small Integer | Int16 |
| Integer | Int32 |
| Big Int | Int64 |
| Date | Date |
| Timestamp(p: 0..3) | Timestamp Milliseconds |
| Timestamp(p >= 4) | Timestamp Microseconds |
| Datetimeoffset(p: 0..3) | Timestamp Milliseconds (UTC) |
| Datetimeoffset(p >= 4) | Timestamp Microseconds (UTC) |
| Varbinary | Byte Array |
| Long Varbinary | Byte Array |
| Binary | Fixed Length Byte Array |
| All others | Utf8 Byte Array |
p is short for precision. s is short for scale. Intervals are inclusive.
Installation
Prerequisites
To work with this tool you need an ODBC driver manager and an ODBC driver for the data source you want to access.
Windows
An ODBC driver manager is already preinstalled on windows. So is the ODBC data sources (64Bit) and ODBC data sources (32Bit) app which you can use to discover which drivers are already available on your system.
Linux
This tool links both at runtime and during build against libodbc.so. To get it you should install unixODBC. You can do this using your systems packet manager. For ubuntu you run:
sudo apt install unixodbc-devOS-X
This tool links both at runtime and during build against libodbc.so. To get it you should install unixODBC. To install it I recommend the homebrew packet manager, which allows you to install it using:
brew install unixodbcDownload binary from GitHub
https://github.com/pacman82/odbc2parquet/releases/latest
Note: Download the 32 Bit version if you want to connect to data sources using 32 Bit drivers and download the 64 Bit version if you want to connect via 64 Bit drivers. It won't work vice versa.
Via Cargo
If you have a rust tool chain installed, you can install this tool via cargo.
cargo install odbc2parquetYou can install cargo from here https://rustup.rs/.
Usage
Query using connection string
odbc2parquet query \
--connection-string "Driver={ODBC Driver 17 for SQL Server};Server=localhost;UID=SA;PWD=<YourStrong@Passw0rd>;" \
out.par \
"SELECT * FROM Birthdays"Query using data source name
odbc2parquet query \
--dsn my_db \
--password "<YourStrong@Passw0rd>" \
--user "SA" \
out.par1 \
"SELECT * FROM Birthdays"List available ODBC drivers
odbc2parquet list-driversList available ODBC data sources
odbc2parquet list-data-sourcesUse parameters in query
odbc2parquet query \
--connection-string "Driver={ODBC Driver 17 for SQL Server};Server=localhost;UID=SA;PWD=<YourStrong@Passw0rd>;" \
out.par \
"SELECT * FROM Birthdays WHERE year > ? and year < ?" \
1990 2010Inserting data into a database
odbc2parquet insert \
--connection-string "Driver={ODBC Driver 17 for SQL Server};Server=localhost;UID=SA;PWD=<YourStrong@Passw0rd>;" \
input.par \
MyTableUse odbc2parquet --help to see all option.
Links
Thanks to @samaguire there is a script for Powershell users which helps you to download a bunch of tables to a folder: https://github.com/samaguire/odbc2parquet-PSscripts