Re: Means to emulate global temporary table

On Wed, Jan 11, 2017 at 4:38 PM, Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

So what makes them temporary as they seem to persist between sessions?

They are temporary in the sense that the content of the table is
per-session, just as a local temporary table would be. That is, each
session has its own independent data set. But, the table is defined and
accessible within the schema as a normal table would be.

While efficiency is not an issue in our usage, on our current server, they
are very efficient because they do not need to handle locking as a normal
table would do because only one session can access the data.

That can be handled with SECURITY DEFINER:
>
>
>
> https://www.postgresql.org/docs/9.6/static/sql-createfunction.html
>
> "EXTERNAL] SECURITY INVOKER
>
> [EXTERNAL] SECURITY DEFINER
>
> SECURITY INVOKER indicates that the function is to be executed with
> the privileges of the user that calls it. That is the default. SECURITY
> DEFINER specifies that the function is to be executed with the privileges
> of the user that created it.
>
> The key word EXTERNAL is allowed for SQL conformance, but it is
> optional since, unlike in SQL, this feature applies to all functions not
> only external one
>

I will look at this in more detail, but, on first reading, I do not quite
see how it helps.

Ian Lewis (www.mstarlabs.com)