weighted_mean
- This Release
- weighted_mean 1.0.1
- Date
- Status
- Stable
- Other Releases
- Abstract
- A weighted mean aggregate function.
- Description
- This library contains a single PostgreSQL extension, an aggregate function called weighted_mean.
- Released By
- rdunklau
- License
- PostgreSQL
- Resources
- Special Files
- Tags
Extensions
- weighted_mean 1.0.0
- A weighted mean aggregate function
README
Weighted Mean extension for PostgreSQL
This extension provides a "weighted mean" aggregate function for postgreql.
The weighted mean is defined as a two columns aggregation function, one containing the measure to be averaged, the second containing the weight of each measure.
This extensions is implemented as a C library.
Installation
You can either install it with the pgxn client:
pgxn install weighted_mean
Or from source:
git clone git://github.com/Kozea/weighted_mean.git make && sudo make install
Then, create the extension in the specific database:
CREATE extension weighted_mean;
Usage
select weighted_mean(unitprice, quantity) from sales;
This is equivalent to:
select case when sum(quantity) = 0 then 0 else sum(unitprice * quantity) / sum(quantity) end from sales;