the freelist, plus per-buffer spinlocks that protect access to individual
shared buffer headers. This requires abandoning a global freelist (since
the freelist is a global contention point), which shoots down ARC and 2Q
as well as plain LRU management. Adopt a clock sweep algorithm instead.
Preliminary results show substantial improvement in multi-backend situations.
adjusting values:
> But to be on the safe side, it would make sense to do something similar
> to the BSD section, and comment about older distributions maybe needing
> to manipulate /proc/kernel/* directly.
Mark Kirkwood
! authentication. Use of this environment variable is not
! recommended for security reasons (some operating systems
! allow non-root users to see process environment variables via
! <application>ps</>); instead consider using the
! <filename>~/.pgpass</> file (see <xref linkend="libpq-pgpass">).
in GetNewTransactionId(). Since the limit value has to be computed
before we run any real transactions, this requires adding code to database
startup to scan pg_database and determine the oldest datfrozenxid.
This can conveniently be combined with the first stage of an attack on
the problem that the 'flat file' copies of pg_shadow and pg_group are
not properly updated during WAL recovery. The code I've added to
startup resides in a new file src/backend/utils/init/flatfiles.c, and
it is responsible for rewriting the flat files as well as initializing
the XID wraparound limit value. This will eventually allow us to get
rid of GetRawDatabaseInfo too, but we'll need an initdb so we can add
a trigger to pg_database.
more variables can be found in the libpq manual section.
Mention .pgpass in the psql manual page section dealing with connection
parameters and point to the libpq section for more details.
Backpatch to 8.0.X.
tests. Contributed by Koju Iijima, review from Neil Conway, Gavin Sherry
and Tom Lane.
Also, fix error in description of WITH CHECK OPTION clause in the CREATE
VIEW reference page: it should be "CASCADED", not "CASCADE".
