Re: [HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-27 Thread Robert Haas
On Thu, Oct 26, 2017 at 11:14 AM, Ashutosh Bapat wrote: > In a nearby thread, we are discussing about atomic commit of > transactions involving foreign transactions. For maintaining > consistency, atomicity of transactions writing to foreign server, we > will need

Re: [HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-26 Thread Ashutosh Bapat
On Wed, Oct 18, 2017 at 5:44 AM, Craig Ringer wrote: > On 18 October 2017 at 02:01, Alexander Korotkov > wrote: >> On Wed, Sep 6, 2017 at 4:42 PM, Alexander Korotkov >> wrote: >>> >>> We're currently blocking writing

Re: [HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-18 Thread Wolfgang Wilhelm
Hi guys, please help me to understand the proposal. Take a simple configuration: Two "live" systems S1 and S2 and for each of them a Replica R1 and R2. So S1 sends data to R1 and S2 to R2. S1 has foreign tables on S2 with write access, meaning you can change a few data from S1 where information

Re: [HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-17 Thread Michael Paquier
On Wed, Oct 18, 2017 at 9:14 AM, Craig Ringer wrote: > Superficially at least, it sounds like a good idea. Indeed. > We should only need a virtual xid when we're working with foreign > tables since we don't do any local heap changes. > > How's it work with savepoints?

Re: [HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-17 Thread Craig Ringer
On 18 October 2017 at 02:01, Alexander Korotkov wrote: > On Wed, Sep 6, 2017 at 4:42 PM, Alexander Korotkov > wrote: >> >> We're currently blocking writing queries on standby if even they are >> modifying contents of foreign tables. But do

[HACKERS] Re: Is anything preventing us from allowing write to foreign tables from standby?

2017-10-17 Thread Alexander Korotkov
On Wed, Sep 6, 2017 at 4:42 PM, Alexander Korotkov < a.korot...@postgrespro.ru> wrote: > We're currently blocking writing queries on standby if even they are > modifying contents of foreign tables. But do we have serious reasons for > that? > Keeping in the mind FDW-sharding, making FDW-tables