https://github.com/adjust/pg-saturated_int
An integer type with saturation arithmetic
https://github.com/adjust/pg-saturated_int
adjust-kpis-team adjust-pg-extension
Last synced: about 1 year ago
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An integer type with saturation arithmetic
- Host: GitHub
- URL: https://github.com/adjust/pg-saturated_int
- Owner: adjust
- License: mit
- Created: 2024-01-12T16:41:07.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2024-02-09T17:06:47.000Z (over 2 years ago)
- Last Synced: 2025-03-09T14:42:04.856Z (over 1 year ago)
- Topics: adjust-kpis-team, adjust-pg-extension
- Language: C
- Homepage:
- Size: 12.7 KB
- Stars: 1
- Watchers: 13
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# pg-saturated_int
An integer type with [saturation arithmetic](https://en.wikipedia.org/wiki/Saturation_arithmetic).
The difference from builtin integer type is that if an input value is out of allowed range
then the error `integer out of range` won't be raised.
## Types
### `saturated_int`
`saturated_int` is an integer type which implements [saturation arithmetic](https://en.wikipedia.org/wiki/Saturation_arithmetic).
Allowed range is `-2147483648` to `+2147483647`.
```sql
-- Cast to saturated_int
select 999999999999999::saturated_int;
saturated_int
---------------
2147483647
select 2147483648::saturated_int;
saturated_int
---------------
2147483647
select (-2147483649)::saturated_int;
saturated_int
---------------
-2147483648
```
## Supported operators
`saturated_int` supports comparison (`<`, `<=`, `<>`, `=`, `>`, `>=`) and arithmetic operators. Here is some examples:
```sql
select 999999999999999::saturated_int > 2147483648::saturated_int;
?column?
----------
f
select 999999999999999::saturated_int = 2147483648::saturated_int;
?column?
----------
t
select 999999999999999::saturated_int * 2147483648::saturated_int;
?column?
------------
2147483647
select (-999999999999999)::saturated_int * 2147483648::saturated_int;
?column?
-------------
-2147483648
select 2147483648::saturated_int / (-1)::saturated_int;
?column?
-------------
-2147483647
```
Note that it is necessary to explicitly cast both of operands to `saturated_int`. Implicit cast isn't supported:
```sql
select 2147483647::int = 2147483648::saturated_int;
ERROR: operator does not exist: integer = saturated_int at character 24
select 2147483647::int * 2147483648::saturated_int;
ERROR: operator does not exist: integer * saturated_int at character 24
```
## Index support
The extension supports `btree` and `hash` indexes.
## Installation from source codes
To install `saturated_int`, execute this in the extension's directory:
```shell
make install
```
> **Notice:** Don't forget to set the `PG_CONFIG` variable (`make PG_CONFIG=...`)
> in case you want to test `saturated_int` on a non-default or custom build of PostgreSQL.
> Read more [here](https://wiki.postgresql.org/wiki/Building_and_Installing_PostgreSQL_Extension_Modules).