Re: Thread safe connection-name mapping in ECPG. Is it required?
От | Michael Meskes |
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Тема | Re: Thread safe connection-name mapping in ECPG. Is it required? |
Дата | |
Msg-id | 20040227073913.GA3502@1 обсуждение исходный текст |
Ответ на | Thread safe connection-name mapping in ECPG. Is it required? (Shridhar Daithankar <shridhar@frodo.hserus.net>) |
Ответы |
Re: Thread safe connection-name mapping in ECPG. Is it
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Список | pgsql-hackers |
On Mon, Feb 23, 2004 at 09:27:40PM +0530, Shridhar Daithankar wrote: > It looks like the mutex protects the connections list in connection.c. I do > not like that from a application developers perspective. > > If I am developing an application and using multiple connections in multiple > threads, I have to store a connection name for each connection as C string. > Of course, I also have to protect it across thread so that I can rightly tell > ecpg what connection I would be talking to next. > > If an application can take care of a C string, it can also take care of a > connection structure. On top of it, it eliminates the list lookup. The > potential performance gain could be worth it if there are hundreds of > connections and a busy website/application server. > > What I wonder is, do we really need to maintain that level of lookup? Can't we > just say a connection is a 'struct connection *' which should be opaque and > should not be touched or poked inside, just like PGConn. I'm not sure I understand you correctly. The SQL standard says you can call your statement as this: exec sql at CONNECTION select 1; Here CONNECTION of course is a string, the name of the connection. So, yes, we have to maintain that list to make sure we get the right connection. Or what were you asking? Michael -- Michael Meskes Email: Michael at Fam-Meskes dot De ICQ: 179140304, AIM/Yahoo: michaelmeskes, Jabber: meskes@jabber.org Go SF 49ers! Go Rhein Fire! Use Debian GNU/Linux! Use PostgreSQL!
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