[fpc-pascal] Lifetime of a database (PostgreSQL) connection

[Michael Van Canneyt]

On Fri, 31 Dec 2010, Mark Morgan Lloyd wrote:

> I've just taken our name server down for maintenance, and noted that a 
> db-aware app I'd left running ground to a halt despite the fact that it was 
> only activating queries, not establishing new (named) connections.
>
> The connection was being made by host name rather than by dotted-quad 
> address, resulting in a long-term handle associated with the TPQConnection 
> object. Whenever a TSQLQuery is activated, it results in the opening of a 
> short-term handle, if I'm reading things correctly associated with a 
> TSQLTransaction object which relies on the host information from the 
> connection object.
>
> My expectation is that these short-term handles should not mandate a name 
> lookup, since the host name or address cannot be specified at this point. Am 
> I being unreasonable?

In order to support multiple transaction, a connection is created for each 
transaction. So if you application creates transactions at regular intervals, 
then it will perform a name lookup each time a transaction is created.


Michael.