> What's the purpose of the updates? If we knew more about what > you're trying to do then maybe we could suggest alternate solutions.
There are two fields (of all the records) I need to update when I insert/update/delete a record. These two fields contain numbers and they act as a link between the records within the table. If I don't update these numbers the link will be broken. Thanks, Ben On Wed, 15 Dec 2004 16:47:53 +1100, Ben <[EMAIL PROTECTED]> wrote: > > What's the purpose of the updates? If we knew more about what > > you're trying to do then maybe we could suggest alternate solutions. > > There are two fields (of all the records) I need to update when I > insert/update/delete a record. These two fields contain numbers and > they act as a link between the records within the table. If I don't > update these numbers the link will be broken. > > > The "Explicit Locking" section of the "Concurrency Control" chapter > > in the documentation describes the available lock modes and their > > conflicts. SELECT acquires ACCESS SHARE; UPDATE, DELETE, and INSERT > > acquire ROW EXCLUSIVE, so it sounds like you want a lock that > > conflicts with ROW EXCLUSIVE but not with ACCESS SHARE. That gives > > the following possibilities: > > > > SHARE > > SHARE ROW EXCLUSIVE > > EXCLUSIVE > > Thank you, I will have another look at the documentation. > > Cheers, > Ben > > On Tue, 14 Dec 2004 20:36:08 -0700, Michael Fuhr <[EMAIL PROTECTED]> wrote: > > On Wed, Dec 15, 2004 at 11:55:34AM +1100, Ben wrote: > > > > > I have this scenario and would like to use lock table for this but I > > > don't know which mode I should use. > > > > > > When I delete/update/insert a record from/to a table, I need to update > > > some fields of all the records in this table. > > > > What's the purpose of the updates? If we knew more about what > > you're trying to do then maybe we could suggest alternate solutions. > > > > > During this process I don't want anyone to insert, update or delete > > > the data but allow them to select the data at the original state. > > > > > > I am currently using: > > > > > > LOCK TABLE tbl_name IN SHARE ROW EXCLUSIVE MODE > > > > > > Is this the correct mode to use? > > > > The "Explicit Locking" section of the "Concurrency Control" chapter > > in the documentation describes the available lock modes and their > > conflicts. SELECT acquires ACCESS SHARE; UPDATE, DELETE, and INSERT > > acquire ROW EXCLUSIVE, so it sounds like you want a lock that > > conflicts with ROW EXCLUSIVE but not with ACCESS SHARE. That gives > > the following possibilities: > > > > SHARE > > SHARE ROW EXCLUSIVE > > EXCLUSIVE > > > > See the documentation for these modes' conflicts and decide which > > is most appropriate. But again, what problem are you trying to > > solve? Maybe there's a better way than locking an entire table. > > > > -- > > Michael Fuhr > > http://www.fuhr.org/~mfuhr/ > > > ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
