Re: Snapshot memory management

Alvaro Herrera wrote:

> To implement this I propose keeping track of four additional pointers in
> SnapshotData: "next" and "prev" in the registered list, and "next" and
> "prev" in the active stack.

FWIW this does not work as proposed because one snapshot can be stored
as active more than once simultaneously.

Back to the drawing board on memory management -- so far I have merged
the two snapshot patches I had (RegisterSnapshot and ActiveSnapshot),
and the result looks reasonably good.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support