https://github.com/grahamedgecombe/pgflate

PostgreSQL module for raw DEFLATE compression/decompression with preset dictionary support
https://github.com/grahamedgecombe/pgflate

deflate postgresql zlib

Last synced: 10 months ago
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PostgreSQL module for raw DEFLATE compression/decompression with preset dictionary support

• Host: GitHub
• URL: https://github.com/grahamedgecombe/pgflate
• Owner: grahamedgecombe
• License: isc
• Created: 2017-01-20T19:36:27.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2017-10-05T16:43:36.000Z (over 8 years ago)
• Last Synced: 2025-04-11T02:04:13.546Z (about 1 year ago)
• Topics: deflate, postgresql, zlib
• Language: C
• Homepage: https://www.grahamedgecombe.com/projects/pgflate
• Size: 11.7 KB
• Stars: 7
• Watchers: 1
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.markdown
  • License: LICENSE

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README

          
# pgflate

## Introduction

pgflate is a PostgreSQL extension that provides functions for deflating and

inflating raw DEFLATE streams, with support for custom dictionaries.

## Prerequisites

* PostgreSQL headers, libraries and PGXS build infrastructure

* `pg_config` must be in your `PATH`

* zlib

## Building

Run `make` to build the extension.

## Installation

Run `make install` as `root` (e.g. with `sudo`) to install the extension.

## Debian package

The repository also contains the files for building a Debian package, which can

be done by running `pg_buildext updatecontrol` followed by `dpkg-buildpackage`.

I distribute pre-built versions for stable amd64 Debian using the

[apt.postgresql.org][pgapt] repository in my [personal APT repository][apt]. Run

`apt-get install postgresql-PGVERSION-flate` as root after setting up the

repository.

## Usage

Run `CREATE EXTENSION flate` to install the extension in the current database.

Two functions are provided:

| Function                                                                       | Return Type |

|--------------------------------------------------------------------------------|-------------|

| deflate(*data* bytea [, *dictionary* bytea [, *level* integer ]]) | `bytea`     |

| inflate(*data* bytea [, *dictionary* bytea ])                     | `bytea`     |

`deflate` compresses the provided `data` and returns a raw DEFLATE stream. A

preset `dictionary` may also be provided. The default compression `level` may

also be overriden, valid values range from `0` (no compression), `1` (best

speed) to `9` (best compression).

If you want to override the compression level without using a dictionary, set

`dictionary` to `NULL`.

`inflate` decompresses the provided DEFLATE stream in `data` and returns the

uncompressed data. A preset `dictionary`, matching the dictionary used to

deflate the data, may also be provided.

## Example

    gpe=# CREATE EXTENSION flate;

    CREATE EXTENSION

    gpe=# SELECT deflate('hello hello hello hello', 'hello', 9);

         deflate

    ------------------

     \xcb00110a182400

    (1 row)

    gpe=# SELECT convert_from(inflate('\xcb00110a182400', 'hello'), 'utf-8');

          convert_from

    -------------------------

     hello hello hello hello

    (1 row)

    gpe=#

## License

This project is available under the terms of the ISC license, which is similar

to the 2-clause BSD license. See the `LICENSE` file for the copyright

information and licensing terms.

[pgapt]: https://wiki.postgresql.org/wiki/Apt

[apt]: https://www.grahamedgecombe.com/apt-repository