On Monday 04 July 2011 10:48:48 Durumdara wrote: > 1.) DataBases need to close the resources kept by Sessions. > 2.) There is need some "border", or a rule to split - which Session is > considered as "finished". So far so good. > The FireBird is uses "DummyPacketInterval" to recognize dead sessions, > EDB uses "Session Timeout" value for it. > The EDB can still alive if network connection lost, if before Timeout > the client also send a sign to the server. > > To I can use PGSQL also, I need to know the limitations, and how to > handle the connections, how to manage them. > > I wondering to PGSQL handle this with living TCP connections, because > this is may out of our control. > If we have a timeout value, we can control, which time we have, and > what time is acceptable for a Session. > For example: some places we have that uses wifi connections are > sometimes broken for just a little period. This is enough to > disconnect, but because of higher "Session Timeout" variable our > DataBase connections still alive without close the applications. > > Another thing is sign (packet). We must do something periodically to > keep alive the connection. For example: every 1 minutes we do some > dummy thing one server, like "select date" or etc. AFAIK postgres doesn't distinguish between a "TCP session" and a "database session" like (if I understand you correctly) FireBird/EDB does. You cannot reconnect and say "hello it's me again from session FOOBAR, can I resume that session ?". I believe you'll have to solve this at the application layer : * Make transactions, locks, temp tables, etc as short-lived as possible (this is always a good thing to do anyway). * If that's still not enough, store your "current working state" in a purpose- built table and add logic in your client to reinitialize session state using that data, and to purge the data after it has been used / timed out. Another thing you could do (but I'm not sure it is a good idea) is to write a proxy application that runs on the server machine and understands your session requirements. Then connect your application to this proxy instead of the database. -- Vincent de Phily Mobile Devices +33 (0) 142 119 325 +353 (0) 85 710 6320 Warning This message (and any associated files) is intended only for the use of its intended recipient and may contain information that is confidential, subject to copyright or constitutes a trade secret. If you are not the intended recipient you are hereby notified that any dissemination, copying or distribution of this message, or files associated with this message, is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. Any views or opinions presented are solely those of the author vincent.dephily@xxxxxxxxxxxxxxxxx and do not necessarily represent those of the company. Although the company has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
