<p dir="ltr"><br /> On Mar 3, 2016 4:47 AM, "Michael Paquier" <<a
href="mailto:michael.paquier@gmail.com">michael.paquier@gmail.com</a>>wrote:<br /> ><br /> > On Wed, Mar 2,
2016at 6:54 PM, Alexander Korotkov<br /> > <<a
href="mailto:a.korotkov@postgrespro.ru">a.korotkov@postgrespro.ru</a>>wrote:<br /> > > If FDWs existed then
PostgresXC/XL were being developed then I believe they<br /> > > would try to build full-featured prototype of
FDWbased sharding. If this<br /> > > prototype succeed then we could make a full roadmap.<br /> ><br /> >
Speakinghere with my XC hat, that's actually the case. A couple of<br /> > years back when I worked on it, there
werediscussions about reusing<br /> > FDW routines for the purpose of XC, which would have been roughly<br /> >
reusingpostgres_fdw + the possibility to send XID, snapshot and<br /> > transaction timestamp to the remote nodes
aftergetting that from the<br /> > GTM (global transaction manager ensuring global data visibility and<br /> >
consistency),and have the logic for query pushdown in the FDW itself<br /> > when planning query on what would have
beenroughly foreign tables<br /> > (not entering in the details here, those would have not been entirely<br /> >
foreigntables). At this point the global picture was not completely<br /> > set, XC being based on 9.1~9.2 and the
FDWbase routines were not as<br /> > extended as they are now. As history has told, this global picture has<br />
>never showed up, though it would should XC have been merged with 9.3.<br /> > The point is that XC would have
movedas using the FDW approach, as a<br /> > set of plugins.<br /> ><br /> > This was a reason behind this
emailof 2013 on -hackers actually:<br /> > <a
href="http://www.postgresql.org/message-id/CAB7nPqTDjf-58wuf-xZ01NKJ7WF0E+EUKgGQHd0igVsOD4hCJQ@mail.gmail.com">http://www.postgresql.org/message-id/CAB7nPqTDjf-58wuf-xZ01NKJ7WF0E+EUKgGQHd0igVsOD4hCJQ@mail.gmail.com</a><p
dir="ltr">Goodto remember! <br /><p dir="ltr">> Michael<br /> ><br /> ><br /> > --<br /> > Sent via
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