Thread: Is this valid?
I am not sure if this is the right mailing list I talk to. Please let me know if I had violated any unwritten rules. :) I have a global variable PGconn* m_pgconn that is the connection handle for connecting to the postgresql database. Can I access/use the handle from multiple threads? Say I have a thread that does some insertion through this handle/database connection(m_pgconn) and also another thread that do some insertion *on the same table* through this handle(m_pgconn), will that break? Thanks -- Wei Weng Network Software Engineer KenCast Inc.
I'm going to ask the crazy question of what language/interface are you using to interact with postgres? Based on my interpretation of your question I'd say that won't break (though one of your queries might fail) but then again I may be totally misreading what you wrote... Robert Treat On Mon, 2002-08-12 at 19:21, Wei Weng wrote: > I am not sure if this is the right mailing list I talk to. Please let me > know if I had violated any unwritten rules. :) > > I have a global variable PGconn* m_pgconn that is the connection handle > for connecting to the postgresql database. Can I access/use the handle > from multiple threads? Say I have a thread that does some insertion > through this handle/database connection(m_pgconn) and also another > thread that do some insertion *on the same table* through this > handle(m_pgconn), will that break? > > Thanks > > > -- > Wei Weng > Network Software Engineer > KenCast Inc. > > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly
I am using C++ and libpq. Thanks Wei -----邮件原件----- 发件人: Robert Treat [mailto:xzilla@users.sourceforge.net] 发送时间: Monday, August 12, 2002 8:10 PM 收件人: Wei Weng 抄送: pgsql-sql@postgresql.org 主题: Re: [SQL] Is this valid? I'm going to ask the crazy question of what language/interface are you using to interact with postgres? Based on my interpretation of your question I'd say that won't break (though one of your queries might fail) but then again I may be totally misreading what you wrote... Robert Treat On Mon, 2002-08-12 at 19:21, Wei Weng wrote: > I am not sure if this is the right mailing list I talk to. Please let me > know if I had violated any unwritten rules. :) > > I have a global variable PGconn* m_pgconn that is the connection handle > for connecting to the postgresql database. Can I access/use the handle > from multiple threads? Say I have a thread that does some insertion > through this handle/database connection(m_pgconn) and also another > thread that do some insertion *on the same table* through this > handle(m_pgconn), will that break? > > Thanks > > > -- > Wei Weng > Network Software Engineer > KenCast Inc. > > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly
Wei Weng wrote: >I am not sure if this is the right mailing list I talk to. Please let me >know if I had violated any unwritten rules. :) > >I have a global variable PGconn* m_pgconn that is the connection handle >for connecting to the postgresql database. Can I access/use the handle >from multiple threads? Say I have a thread that does some insertion >through this handle/database connection(m_pgconn) and also another >thread that do some insertion *on the same table* through this >handle(m_pgconn), will that break? > >Thanks > > > > I don't think it's a good idea to use global variable in multi-thread environment. I think use different handle in differents is better. libpq is thread safe, but it doesn't necessary mean that you could free of your own code. regards laser
On Mon, 2002-08-12 at 23:58, Weiping He wrote: > Wei Weng wrote: > > >I am not sure if this is the right mailing list I talk to. Please let me > >know if I had violated any unwritten rules. :) > > > >I have a global variable PGconn* m_pgconn that is the connection handle > >for connecting to the postgresql database. Can I access/use the handle > >from multiple threads? Say I have a thread that does some insertion > >through this handle/database connection(m_pgconn) and also another > >thread that do some insertion *on the same table* through this > >handle(m_pgconn), will that break? > > > >Thanks > > > > > > > > > I don't think it's a good idea to use global variable > in multi-thread environment. > I think use different handle in differents is better. > > libpq is thread safe, but it doesn't necessary mean > that you could free of your own code. > Is it going to be resource draining if I make lots of connections in a very short time? -- Wei Weng Network Software Engineer KenCast Inc.