When the old type is binary coercible to the new type and the using
clause does not change the column contents, we can avoid a full table
rewrite, though any indexes on the affected columns will still need
to be rebuilt. This applies, for example, when changing a varchar
column to be of type text.
The prior coding assumed that the set of operations that force a
rewrite is identical to the set of operations that must be propagated
to tables making use of the affected table's rowtype. This is
no longer true: even though the tuples in those tables wouldn't
need to be modified, the data type change invalidate indexes built
using those composite type columns. Indexes on the table we're
actually modifying can be invalidated too, of course, but the
existing machinery is sufficient to handle that case.
Along the way, add some debugging messages that make it possible
to understand what operations ALTER TABLE is actually performing
in these cases.
Noah Misch and Robert Haas
Arrange for the control files to be in $SHAREDIR/extension not
$SHAREDIR/contrib, since we're generally trying to deprecate the term
"contrib" and this is a once-in-many-moons opportunity to get rid of it in
install paths. Fix PGXS to install the $EXTENSION file into that directory
no matter what MODULEDIR is set to; a nondefault MODULEDIR should only
affect the script and secondary extension files. Fix the control file
directory parameter to be interpreted relative to $SHAREDIR, to avoid a
surprising disconnect between how you specify that and what you set
MODULEDIR to.
Per discussion with David Wheeler.
This follows recent discussions, so it's quite a bit different from
Dimitri's original. There will probably be more changes once we get a bit
of experience with it, but let's get it in and start playing with it.
This is still just core code. I'll start converting contrib modules
shortly.
Dimitri Fontaine and Tom Lane
the standby has written, flushed, and applied the WAL. At the moment, this
is for informational purposes only, the values are only shown in
pg_stat_replication system view, but in the future they will also be needed
for synchronous replication.
Extracted from Simon riggs' synchronous replication patch by Robert Haas, with
some tweaking by me.
Tracks one counter for each database, which is reset whenever
the statistics for any individual object inside the database is
reset, and one counter for the background writer.
Tomas Vondra, reviewed by Greg Smith
This is an essential component of making the extension feature usable;
first because it's needed in the process of converting an existing
installation containing "loose" objects of an old contrib module into
the extension-based world, and second because we'll have to use it
in pg_dump --binary-upgrade, as per recent discussion.
Loosely based on part of Dimitri Fontaine's ALTER EXTENSION UPGRADE
patch.
Specifying this option makes the server not wait for the
xlog to be archived, or emit a warning that it can't,
instead leaving the responsibility with the client.
This is useful when the log is being streamed using
the streaming protocol in parallel with the backup,
without having log archiving enabled.
This patch adds the server infrastructure to support extensions.
There is still one significant loose end, namely how to make it play nice
with pg_upgrade, so I am not yet committing the changes that would make
all the contrib modules depend on this feature.
In passing, fix a disturbingly large amount of breakage in
AlterObjectNamespace() and callers.
Dimitri Fontaine, reviewed by Anssi Kääriäinen,
Itagaki Takahiro, Tom Lane, and numerous others
This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.
Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
new recovery.conf parameter recovery_target_name allows PITR to
specify named points as recovery targets.
Jaime Casanova, reviewed by Euler Taveira de Oliveira, plus minor edits
FK constraints that are marked NOT VALID may later be VALIDATED, which uses an
ShareUpdateExclusiveLock on constraint table and RowShareLock on referenced
table. Significantly reduces lock strength and duration when adding FKs.
New state visible from psql.
Simon Riggs, with reviews from Marko Tiikkaja and Robert Haas
Waiting for relation locks can lead to starvation - it pins down an
autovacuum worker for as long as the lock is held. But if we're doing
an anti-wraparound vacuum, then we still wait; maintenance can no longer
be put off.
To assist with troubleshooting, if log_autovacuum_min_duration >= 0,
we log whenever an autovacuum or autoanalyze is skipped for this reason.
Per a gripe by Josh Berkus, and ensuing discussion.
Until now, our Serializable mode has in fact been what's called Snapshot
Isolation, which allows some anomalies that could not occur in any
serialized ordering of the transactions. This patch fixes that using a
method called Serializable Snapshot Isolation, based on research papers by
Michael J. Cahill (see README-SSI for full references). In Serializable
Snapshot Isolation, transactions run like they do in Snapshot Isolation,
but a predicate lock manager observes the reads and writes performed and
aborts transactions if it detects that an anomaly might occur. This method
produces some false positives, ie. it sometimes aborts transactions even
though there is no anomaly.
To track reads we implement predicate locking, see storage/lmgr/predicate.c.
Whenever a tuple is read, a predicate lock is acquired on the tuple. Shared
memory is finite, so when a transaction takes many tuple-level locks on a
page, the locks are promoted to a single page-level lock, and further to a
single relation level lock if necessary. To lock key values with no matching
tuple, a sequential scan always takes a relation-level lock, and an index
scan acquires a page-level lock that covers the search key, whether or not
there are any matching keys at the moment.
A predicate lock doesn't conflict with any regular locks or with another
predicate locks in the normal sense. They're only used by the predicate lock
manager to detect the danger of anomalies. Only serializable transactions
participate in predicate locking, so there should be no extra overhead for
for other transactions.
Predicate locks can't be released at commit, but must be remembered until
all the transactions that overlapped with it have completed. That means that
we need to remember an unbounded amount of predicate locks, so we apply a
lossy but conservative method of tracking locks for committed transactions.
If we run short of shared memory, we overflow to a new "pg_serial" SLRU
pool.
We don't currently allow Serializable transactions in Hot Standby mode.
That would be hard, because even read-only transactions can cause anomalies
that wouldn't otherwise occur.
Serializable isolation mode now means the new fully serializable level.
Repeatable Read gives you the old Snapshot Isolation level that we have
always had.
Kevin Grittner and Dan Ports, reviewed by Jeff Davis, Heikki Linnakangas and
Anssi Kääriäinen
String are converted to UTF8 on the way into perl and to the
database encoding on the way back. This avoids a number of
observed anomalies, and ensures Perl a consistent view of the
world.
Some minor code cleanups are also accomplished.
Alex Hunsaker, reviewed by Andy Colson.
Remove the claim that ALTER TABLE .. SET DATA TYPE is the fastest way of
rewriting a table, since it no longer is.
Noah Misch and Robert Haas, based on a suggestion from Tom Lane.
src/pl/plpgsql/src/plerrcodes.h, src/include/utils/errcodes.h, and a
big chunk of errcodes.sgml are now automatically generated from a single
file, src/backend/utils/errcodes.txt.
Jan Urbański, reviewed by Tom Lane.
Add the current xlog insert location to the response of
IDENTIFY_SYSTEM, and adds result sets containing start
and stop location of backups to BASE_BACKUP responses.
Prior to 9.0, restartpoints never created, deleted, or recycled WAL
files, but now they can. This code makes log_checkpoints treat
checkpoints and restartpoints symmetrically. It also adjusts up
the documentation of the parameter to mention restartpoints.
Fujii Masao. Docs by me, as suggested by Itagaki Takahiro.
This allows the language-specific try/catch construct to catch and
handle exceptions arising from SPI calls, matching the behavior of
other PLs.
As an additional bonus you no longer get all the ugly "unrecognized
error in PLy_spi_execute_query" errors.
Jan Urbański, reviewed by Steve Singer
Unlike Btree-based LIKE optimization, this works for non-left-anchored
search patterns. The effectiveness of the search depends on how many
trigrams can be extracted from the pattern. (The worst case, with no
trigrams, degrades to a full-table scan, so this isn't a panacea. But
it can be very useful.)
Alexander Korotkov, reviewed by Jan Urbanski
Previously reported as ERRCODE_ADMIN_SHUTDOWN, this case is now
reported as ERRCODE_T_R_DATABASE_DROPPED. No message text change.
Unlikely to happen on most servers, so low impact change to allow
session poolers to correctly handle this situation.
Tatsuo Ishii, edits by me, review by Robert Haas
Document how to build 64 bit Windows binaries using the MinGW64 tool set.
Remove recommendation against using Mingw as a build platform.
Be more specific about when Cygwin is useful and when it's not, in
particular note its usefulness for running psql, and
add a note about building on Cygwin in non-C locales.
Per recent discussions.
Operation", merged from upgrade sections in "Installation from Source
Code" and "Backup and Restore". This now gives a single place for all
upgrade information.
With this patch, pg_basebackup doesn't write a backup_label file in the
data directory, so it doesn't interfere with a pg_start/stop_backup() based
backup anymore. backup_label is still included in the backup, but it is
injected directly into the tar stream.
Heikki Linnakangas, reviewed by Fujii Masao and Magnus Hagander.
When included, this makes the base backup a complete working
"clone" of the initial database, ready to have a postmaster
started against it without the need to set up any log archiving
or similar.
Magnus Hagander, reviewed by Fujii Masao and Heikki Linnakangas
Although this improves the style, an ulterior motive is to keep the two
table links from breaking across lines in PDF output, per complaint from
Josh Kupershmidt.
The link to the CREATE CONVERSION manual page was split across a page
boundary in the PDF output, leading to "\pdfendlink ended up in different
nesting level than \pdfstartlink" error while building PDFs.
It wouldn't be worth changing text that's undergoing active editing to
avoid this, since other editing might result in moving the link away from
the page end anyway. But this paragraph has been static for a long time,
so might as well fix it to prevent it from being an issue in future.
There isn't any need to track this state on a table-wide basis, and trying
to do so introduces undesirable semantic fuzziness. Move the flag to
pg_index, where it clearly describes just a single index and can be
immutable after index creation.
This feature allows a unique or pkey constraint to be created using an
already-existing unique index. While the constraint isn't very
functionally different from the bare index, it's nice to be able to do that
for documentation purposes. The main advantage over just issuing a plain
ALTER TABLE ADD UNIQUE/PRIMARY KEY is that the index can be created with
CREATE INDEX CONCURRENTLY, so that there is not a long interval where the
table is locked against updates.
On the way, refactor some of the code in DefineIndex() and index_create()
so that we don't have to pass through those functions in order to create
the index constraint's catalog entries. Also, in parse_utilcmd.c, pass
around the ParseState pointer in struct CreateStmtContext to save on
notation, and add error location pointers to some error reports that didn't
have one before.
Gurjeet Singh, reviewed by Steve Singer and Tom Lane
This is still pretty rough - among other things, the documentation
needs work, and the messages need a visit from the style police -
but this gets the basic framework in place.
KaiGai Kohei
This tool makes it possible to do the pg_start_backup/
copy files/pg_stop_backup step in a single command.
There are still some steps to be done before this is a
complete backup solution, such as the ability to stream
the required WAL logs, but it's still usable, and
could do with some buildfarm coverage.
In passing, make the checkpoint request optionally
fast instead of hardcoding it.
Magnus Hagander, reviewed by Fujii Masao and Dimitri Fontaine
If wal_buffers is initially set to -1 (which is now the default), it's
replaced by 1/32nd of shared_buffers, with a minimum of 8 (the old default)
and a maximum of the XLOG segment size. The allowed range for manual
settings is still from 4 up to whatever will fit in shared memory.
Greg Smith, with implementation correction by me.
Actually rename the program, rather than just claiming we did. Hook it
into the build system. Get rid of useless dependency on libpq. Clean up
#include list and messy whitespace.
Makes it easier to parse mainly the BASE_BACKUP command
with it's options, and avoids having to manually deal
with quoted identifiers in the label (previously broken),
and makes it easier to add new commands and options in
the future.
In passing, refactor the case statement in the walsender
to put each command in it's own function.
Fix broken test for pre-existing postmaster, caused by wrong code for
appending lines to the lockfile; don't write a failed listen_address
setting into the lockfile; don't arbitrarily change the location of the
data directory in the lockfile compared to previous releases; provide more
consistent and useful definitions of the socket path and listen_address
entries; avoid assuming that pg_ctl has the same DEFAULT_PGSOCKET_DIR as
the postmaster; assorted code style improvements.
Instead, run them in the encoding that the locale selects, which is
more representative of real use.
Also document how locale and encoding for regression test runs can be
selected.