Previously this state was represented by whether the view's disk file had
zero or nonzero size, which is problematic for numerous reasons, since it's
breaking a fundamental assumption about heap storage. This was done to
allow unlogged matviews to revert to unpopulated status after a crash
despite our lack of any ability to update catalog entries post-crash.
However, this poses enough risk of future problems that it seems better to
not support unlogged matviews until we can find another way. Accordingly,
revert that choice as well as a number of existing kluges forced by it
in favor of creating a pg_class.relispopulated flag column.
The initial implementation of this feature was really unsupportable,
because it's relying on the physical size of an on-disk file to carry the
relation's populated/unpopulated state, which is at least a modularity
violation and could have serious long-term consequences. We could say that
an unlogged matview goes to empty on crash, but not everybody likes that
definition, so let's just remove the feature for 9.3. We can add it back
when we have a less klugy implementation.
I left the grammar and tab-completion support for CREATE UNLOGGED
MATERIALIZED VIEW in place, since it's harmless and allows delivering a
more specific error message about the unsupported feature.
I'm committing this separately to ease identification of what should be
reverted when/if we are able to re-enable the feature.
Restore 4-byte designation for docs. Fix 9.3 doc query to properly pad
to four digits.
Backpatch to all active branches
Per suggestions from Ian Lawrence Barwick
Previously, libpq and the backend had opposite ideas about whether
it was necessary for the client to send a CopyDone message after
receiving an ErrorResponse, making it impossible to cleanly exit
COPY BOTH mode. Fix libpq so that works correctly, adopting the
backend's notion that an ErrorResponse kills the copy in both
directions.
Adjust receivelog.c to avoid a degradation in the quality of the
resulting error messages. libpqwalreceiver.c is already doing
the right thing, so no adjustment needed there.
Add an explicit statement to the documentation explaining how
this part of the protocol is supposed to work, in the hopes of
avoiding future confusion in this area.
Since the consequences of all this confusion are very limited,
especially in the back-branches where no client ever attempts
to exit COPY BOTH mode without closing the connection entirely,
no back-patch.
This changes the behavior of the start and stop actions to exit
successfully if the server was already started or stopped.
This changes the default behavior of the start action: Before, if the
server was already running, it would print a message and succeed. Now,
that situation will result in an error. When running in idempotent
mode, no message is printed and pg_ctl exits successfully.
It was considered to just make the idempotent behavior the default and
only option, but pg_upgrade needs the old behavior.
This wasn't addressed in the original patch, but it doesn't take very
much additional code to cover the case, so let's get it done.
Since pg_trgm 1.1 hasn't been released yet, I just changed the definition
of what's in it, rather than inventing a 1.2.
