Re: [HACKERS] proposal: schema variables

2018-03-20 18:38 GMT+01:00 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:

> Hi
>
> I am sending new update. The code is less ugly, and the current
> functionality is +/- final for first stage. It should be good enough for
> playing and testing this concept.
>
> What is supported:
>
> 1. scalar, composite and array variables
> 2. composite can be defined on place or some composite type can be used
> 3. variable, or any field of variable, can have defined default value
> 4. variable is database object - the access rights are required
> 5. the values are stored in binary form with defined typmod
>
> An usage is very simple:
>
> postgres=# create variable foo as numeric default 0;
> CREATE VARIABLE
> postgres=# select foo;
> ┌─────┐
> │ foo │
> ╞═════╡
> │ 0 │
> └─────┘
> (1 row)
>
> postgres=# let foo = pi();
> LET
> postgres=# select foo;
> ┌──────────────────┐
> │ foo │
> ╞══════════════════╡
> │ 3.14159265358979 │
> └──────────────────┘
> (1 row)
>
> postgres=# create variable boo as (x numeric default 0, y numeric default
> 0);
> CREATE VARIABLE
> postgres=# let boo.x = 100;
> LET
> postgres=# select boo;
> ┌─────────┐
> │ boo │
> ╞═════════╡
> │ (100,0) │
> └─────────┘
> (1 row)
>
> postgres=# select boo.x;
> ┌─────┐
> │ x │
> ╞═════╡
> │ 100 │
> └─────┘
> (1 row)
>
> Please try it.
>

small fix - support for SQL functions

>
> Regards
>
> Pavel
>