Re: How to watch for schema changes

On 12/3/18 5:29 AM, Igor Korot wrote:
> Hi, Adrian,
> 
> On Mon, Dec 3, 2018 at 5:15 PM Adrian Klaver <adrian.klaver@aklaver.com> wrote:
>>
>> On 12/3/18 3:00 PM, Igor Korot wrote:
>>> Hi, Adrian,
>>>

>>>
>>> What I mean to say was "no schema changes/server changes that comes
>>> independently
>>> of the program install". Or something to that extent.
>>
>> Which circles back around to the same question:
>>
>> If there are to be no schema changes after the install why track them on
>> subsequent connections?
>>
>> Or maybe an explanation of what you are trying to achieve would make
>> things clearer?
> 
> Ok, it probably will make things clearer.
> So I install my program perform some queries and exit.
> At the same time if the user will create or delete a table the program should
> pick up those changes and act accordingly.

So do you want the user to change the schema?

Or could you use permissions to stop that?

I am just seeing a difficult problem trying to divine user intent from 
schema changes.

> 
> I was hoping to do the watching initialization dynamically, but it looks as it
> is more pain and I can probably try to execute the script during the
> installation.
> 
> So basically I will create the function in C, compile it and then
> during the program installation
> create a trigger with that function.
> Then in my program I will execute "LISTEN" command and act accordingly.
> 
> Am I right?

Not sure I have never tried LISTEN on event trigger output.

> 
> And executing LISTEN will also work for ODBC connection, right?

Again not something I am familiar with. Someone else on this list may be 
able to answer that. Or there is:

https://www.postgresql.org/list/pgsql-odbc/

> 
> Thank you.
> 
>>
>>
>>
>>>
>>> Sorry, ESL person here.
>>>
>>> Thank you.
>>>
>>>>
>>>>>
>>>>> But I will probably create it on every connection and delete on the
>>>>> disconnect (see above).
>>>>>
>>>>
>>>> --
>>>> Adrian Klaver
>>>> adrian.klaver@aklaver.com
>>>
>>
>>
>> --
>> Adrian Klaver
>> adrian.klaver@aklaver.com
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com