Commit Graph

19327 Commits

Author SHA1 Message Date
Tom Lane 12d46ac392 Improve documentation about our XML functionality.
Add a section explaining how our XML features depart from current
versions of the SQL standard.  Update and clarify the descriptions
of some XML functions.

Chapman Flack, reviewed by Ryan Lambert

Discussion: https://postgr.es/m/5BD1284C.1010305@anastigmatix.net
Discussion: https://postgr.es/m/5C81F8C0.6090901@anastigmatix.net
Discussion: https://postgr.es/m/CAN-V+g-6JqUQEQZ55Q3toXEN6d5Ez5uvzL4VR+8KtvJKj31taw@mail.gmail.com
2019-04-01 16:20:22 -04:00
Tom Lane b2b819019f Add volatile qualifier missed in commit 2e616dee9.
Noted by Pavel Stehule

Discussion: https://postgr.es/m/CAFj8pRAaGO5FX7bnP3E=mRssoK8y5T78x7jKy-vDiyS68L888Q@mail.gmail.com
2019-04-01 14:37:25 -04:00
Peter Eisentraut cc8d415117 Unified logging system for command-line programs
This unifies the various ad hoc logging (message printing, error
printing) systems used throughout the command-line programs.

Features:

- Program name is automatically prefixed.

- Message string does not end with newline.  This removes a common
  source of inconsistencies and omissions.

- Additionally, a final newline is automatically stripped, simplifying
  use of PQerrorMessage() etc., another common source of mistakes.

- I converted error message strings to use %m where possible.

- As a result of the above several points, more translatable message
  strings can be shared between different components and between
  frontends and backend, without gratuitous punctuation or whitespace
  differences.

- There is support for setting a "log level".  This is not meant to be
  user-facing, but can be used internally to implement debug or
  verbose modes.

- Lazy argument evaluation, so no significant overhead if logging at
  some level is disabled.

- Some color in the messages, similar to gcc and clang.  Set
  PG_COLOR=auto to try it out.  Some colors are predefined, but can be
  customized by setting PG_COLORS.

- Common files (common/, fe_utils/, etc.) can handle logging much more
  simply by just using one API without worrying too much about the
  context of the calling program, requiring callbacks, or having to
  pass "progname" around everywhere.

- Some programs called setvbuf() to make sure that stderr is
  unbuffered, even on Windows.  But not all programs did that.  This
  is now done centrally.

Soft goals:

- Reduces vertical space use and visual complexity of error reporting
  in the source code.

- Encourages more deliberate classification of messages.  For example,
  in some cases it wasn't clear without analyzing the surrounding code
  whether a message was meant as an error or just an info.

- Concepts and terms are vaguely aligned with popular logging
  frameworks such as log4j and Python logging.

This is all just about printing stuff out.  Nothing affects program
flow (e.g., fatal exits).  The uses are just too varied to do that.
Some existing code had wrappers that do some kind of print-and-exit,
and I adapted those.

I tried to keep the output mostly the same, but there is a lot of
historical baggage to unwind and special cases to consider, and I
might not always have succeeded.  One significant change is that
pg_rewind used to write all error messages to stdout.  That is now
changed to stderr.

Reviewed-by: Donald Dong <xdong@csumb.edu>
Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru>
Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 20:01:35 +02:00
Alexander Korotkov b4cc19ab01 Throw error in jsonb_path_match() when result is not single boolean
jsonb_path_match() checks if jsonb document matches jsonpath query.  Therefore,
jsonpath query should return single boolean.  Currently, if result of jsonpath
is not a single boolean, NULL is returned independently whether silent mode
is on or off.  But that appears to be wrong when silent mode is off.  This
commit makes jsonb_path_match() throw an error in this case.

Author: Nikita Glukhov
2019-04-01 18:09:20 +03:00
Alexander Korotkov 2e643501e5 Restrict some cases in parsing numerics in jsonpath
Jsonpath now accepts integers with leading zeroes and floats starting with
a dot.  However, SQL standard requires to follow JSON specification, which
doesn't allow none of these cases.  Our json[b] datatypes also restrict that.
So, restrict it in jsonpath altogether.

Author: Nikita Glukhov
2019-04-01 18:09:09 +03:00
Alexander Korotkov 0a02e2ae02 GIN support for @@ and @? jsonpath operators
This commit makes existing GIN operator classes jsonb_ops and json_path_ops
support "jsonb @@ jsonpath" and "jsonb @? jsonpath" operators.  Basic idea is
to extract statements of following form out of jsonpath.

 key1.key2. ... .keyN = const

The rest of jsonpath is rechecked from heap.

Catversion is bumped.

Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Author: Nikita Glukhov, Alexander Korotkov
Reviewed-by: Jonathan Katz, Pavel Stehule
2019-04-01 18:08:52 +03:00
Peter Eisentraut 7241911782 Catch syntax error in generated column definition
The syntax

    GENERATED BY DEFAULT AS (expr)

is not allowed but we have to accept it in the grammar to avoid
shift/reduce conflicts because of the similar syntax for identity
columns.  The existing code just ignored this, incorrectly.  Add an
explicit error check and a bespoke error message.

Reported-by: Justin Pryzby <pryzby@telsasoft.com>
2019-04-01 10:46:37 +02:00
Michael Paquier 4ae7f02b03 Fix thinko in allocation call during MVC list deserialization
Spotted by Coverity.
2019-04-01 14:16:27 +09:00
Noah Misch 5a907404b5 Update HINT for pre-existing shared memory block.
One should almost always terminate an old process, not use a manual
removal tool like ipcrm.  Removal of the ipcclean script eleven years
ago (39627b1ae6) and its non-replacement
corroborate that manual shm removal is now a niche goal.  Back-patch to
9.4 (all supported versions).

Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.

Discussion: https://postgr.es/m/20180812064815.GB2301738@rfd.leadboat.com
2019-03-31 19:32:48 -07:00
Andres Freund bfbcad478f tableam: bitmap table scan.
This moves bitmap heap scan support to below an optional tableam
callback. It's optional as the whole concept of bitmap heapscans is
fairly block specific.

This basically moves the work previously done in bitgetpage() into the
new scan_bitmap_next_block callback, and the direct poking into the
buffer done in BitmapHeapNext() into the new scan_bitmap_next_tuple()
callback.

The abstraction is currently somewhat leaky because
nodeBitmapHeapscan.c's prefetching and visibilitymap based logic
remains - it's likely that we'll later have to move more into the
AM. But it's not trivial to do so without introducing a significant
amount of code duplication between the AMs, so that's a project for
later.

Note that now nodeBitmapHeapscan.c and the associated node types are a
bit misnamed. But it's not clear whether renaming wouldn't be a cure
worse than the disease. Either way, that'd be best done in a separate
commit.

Author: Andres Freund
Reviewed-By: Robert Haas (in an older version)
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-31 18:37:57 -07:00
Andres Freund 73c954d248 tableam: sample scan.
This moves sample scan support to below tableam. It's not optional as
there is, in contrast to e.g. bitmap heap scans, no alternative way to
perform tablesample queries. If an AM can't deal with the block based
API, it will have to throw an ERROR.

The tableam callbacks for this are block based, but given the current
TsmRoutine interface, that seems to be required.

The new interface doesn't require TsmRoutines to perform visibility
checks anymore - that requires the TsmRoutine to know details about
the AM, which we want to avoid.  To continue to allow taking the
returned number of tuples account SampleScanState now has a donetuples
field (which previously e.g. existed in SystemRowsSamplerData), which
is only incremented after the visibility check succeeds.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-31 18:37:57 -07:00
Andres Freund 4bb50236eb tableam: Formatting and other minor cleanups.
The superflous heapam_xlog.h includes were reported by Peter
Geoghegan.
2019-03-31 18:16:53 -07:00
Peter Geoghegan 76a39f2295 Fix nbtree high key "continuescan" row compare bug.
Commit 29b64d1d mishandled skipping over truncated high key attributes
during row comparisons.  The row comparison key matching loop would loop
forever when a truncated attribute was encountered for a row compare
subkey.  Fix by following the example of other code in the loop: advance
the current subkey, or break out of the loop when the last subkey is
reached.

Add test coverage for the relevant _bt_check_rowcompare() code path.
The new test case is somewhat tied to nbtree implementation details,
which isn't ideal, but seems unavoidable.
2019-03-31 17:24:04 -07:00
Tom Lane 9fd4de119c Compute root->qual_security_level in a less random place.
We can set this up once and for all in subquery_planner's initial survey
of the flattened rangetable, rather than incrementally adjusting it in
build_simple_rel.  The previous approach made it rather hard to reason
about exactly when the value would be available, and we were definitely
using it in some places before the final value was computed.

Noted while fooling around with Amit Langote's patch to delay creation
of inheritance child rels.  That didn't break this code, but it made it
even more fragile, IMO.
2019-03-31 13:47:41 -04:00
Michael Paquier 2aa6e331ea Skip redundant anti-wraparound vacuums
An anti-wraparound vacuum has to be by definition aggressive as it needs
to work on all the pages of a relation.  However it can happen that due
to some concurrent activity an anti-wraparound vacuum is marked as
non-aggressive, which makes it redundant with a previous run, and
it is actually useless as an anti-wraparound vacuum should process all
the pages of a relation.  This commit makes such vacuums to be skipped.

An anti-wraparound vacuum not aggressive can be found easily by mixing
low values of autovacuum_freeze_max_age (to control anti-wraparound) and
autovacuum_freeze_table_age (to control the aggressiveness).

28a8fa9 has added some extra logging printing all the possible
combinations of anti-wraparound and aggressive vacuums, which now gets
simplified as an anti-wraparound vacuum also non-aggressive gets
skipped.

Per discussion mainly between Andrew Dunstan, Robert Haas, Álvaro
Herrera, Kyotaro Horiguchi, Masahiko Sawada, and myself.

Author: Kyotaro Horiguchi, Michael Paquier
Reviewed-by: Andrew Dunstan, Álvaro Herrera
Discussion: https://postgr.es/m/20180914153554.562muwr3uwujno75@alvherre.pgsql
2019-03-31 22:59:12 +09:00
Andres Freund 696d78469f tableam: Move heap specific logic from estimate_rel_size below tableam.
This just moves the table/matview[/toast] determination of relation
size to a callback, and uses a copy of the existing logic to implement
that callback for heap.

It probably would make sense to also move the index specific logic
into a callback, so the metapage handling (and probably more) can be
index specific. But that's a separate task.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-30 19:26:36 -07:00
Andres Freund 737a292b5d tableam: VACUUM and ANALYZE support.
This is a relatively straightforward move of the current
implementation to sit below tableam. As the current analyze sampling
implementation is pretty inherently block based, the tableam analyze
interface is as well. It might make sense to generalize that at some
point, but that seems like a larger project that shouldn't be
undertaken at the same time as the introduction of tableam.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-30 19:25:58 -07:00
Tomas Vondra 0f5493fdf1 Fix typo
Author: John Naylor
2019-03-31 03:29:58 +02:00
Tom Lane 428b260f87 Speed up planning when partitions can be pruned at plan time.
Previously, the planner created RangeTblEntry and RelOptInfo structs
for every partition of a partitioned table, even though many of them
might later be deemed uninteresting thanks to partition pruning logic.
This incurred significant overhead when there are many partitions.
Arrange to postpone creation of these data structures until after
we've processed the query enough to identify restriction quals for
the partitioned table, and then apply partition pruning before not
after creation of each partition's data structures.  In this way
we need not open the partition relations at all for partitions that
the planner has no real interest in.

For queries that can be proven at plan time to access only a small
number of partitions, this patch improves the practical maximum
number of partitions from under 100 to perhaps a few thousand.

Amit Langote, reviewed at various times by Dilip Kumar, Jesper Pedersen,
Yoshikazu Imai, and David Rowley

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp
2019-03-30 18:58:55 -04:00
Tomas Vondra ad3107b973 Fix compiler warnings in multivariate MCV code
Compiler warnings were observed on gcc 3.4.6 (on gaur).

The assert is unnecessary, as the indexes are uint16 and so always >= 0.

Reported-by: Tom Lane
2019-03-30 18:43:16 +01:00
Tomas Vondra ea4e1c0e8f Additional fixes of memory alignment in pg_mcv_list code
Commit d85e0f366a tried to fix memory alignment issues in serialization
and deserialization of pg_mcv_list values, but it was a few bricks shy.
The arrays of uint16 indexes in serialized items was not aligned, and
the both the values and isnull flags were using the same pointer.

Per investigation by Tom Lane on gaur.
2019-03-30 18:34:59 +01:00
Tom Lane 7ad6498fd5 Avoid crash in partitionwise join planning under GEQO.
While trying to plan a partitionwise join, we may be faced with cases
where one or both input partitions for a particular segment of the join
have been pruned away.  In HEAD and v11, this is problematic because
earlier processing didn't bother to make a pruned RelOptInfo fully
valid.  With an upcoming patch to make partition pruning more efficient,
this'll be even more problematic because said RelOptInfo won't exist at
all.

The existing code attempts to deal with this by retroactively making the
RelOptInfo fully valid, but that causes crashes under GEQO because join
planning is done in a short-lived memory context.  In v11 we could
probably have fixed this by switching to the planner's main context
while fixing up the RelOptInfo, but that idea doesn't scale well to the
upcoming patch.  It would be better not to mess with the base-relation
data structures during join planning, anyway --- that's just a recipe
for order-of-operations bugs.

In many cases, though, we don't actually need the child RelOptInfo,
because if the input is certainly empty then the join segment's result
is certainly empty, so we can skip making a join plan altogether.  (The
existing code ultimately arrives at the same conclusion, but only after
doing a lot more work.)  This approach works except when the pruned-away
partition is on the nullable side of a LEFT, ANTI, or FULL join, and the
other side isn't pruned.  But in those cases the existing code leaves a
lot to be desired anyway --- the correct output is just the result of
the unpruned side of the join, but we were emitting a useless outer join
against a dummy Result.  Pending somebody writing code to handle that
more nicely, let's just abandon the partitionwise-join optimization in
such cases.

When the modified code skips making a join plan, it doesn't make a
join RelOptInfo either; this requires some upper-level code to
cope with nulls in part_rels[] arrays.  We would have had to have
that anyway after the upcoming patch.

Back-patch to v11 since the crash is demonstrable there.

Discussion: https://postgr.es/m/8305.1553884377@sss.pgh.pa.us
2019-03-30 12:48:32 -04:00
Peter Eisentraut fc22b6623b Generated columns
This is an SQL-standard feature that allows creating columns that are
computed from expressions rather than assigned, similar to a view or
materialized view but on a column basis.

This implements one kind of generated column: stored (computed on
write).  Another kind, virtual (computed on read), is planned for the
future, and some room is left for it.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com
2019-03-30 08:15:57 +01:00
Peter Eisentraut 6b8b5364dd Small code simplification for REINDEX CONCURRENTLY
This was left over from an earlier code structure.
2019-03-30 07:16:24 +01:00
Peter Geoghegan 9c7fb7e6d8 Tweak some nbtree-related code comments. 2019-03-29 12:29:05 -07:00
Tomas Vondra d85e0f366a Fix memory alignment in pg_mcv_list serialization
Blind attempt at fixing ia64, hppa an sparc builds.

The serialized representation of MCV lists did not enforce proper memory
alignment for internal fields, resulting in deserialization issues on
platforms that are more sensitive to this (ia64, sparc and hppa).

This forces a catalog version bump, because the layout of serialized
pg_mcv_list changes.

Broken since 7300a699.
2019-03-29 19:06:38 +01:00
Andres Freund ffa8444ce4 tableam: Comment fixes.
Author: Haribabu Kommi
Discussion: CAJrrPGeeYOqP3hkZyohDx_8dot4zvPuPMDBmhJ=iC85cTBNeYw@mail.gmail.com
2019-03-29 08:17:26 -07:00
Robert Haas 41b54ba78e Allow existing VACUUM options to take a Boolean argument.
This makes VACUUM work more like EXPLAIN already does without changing
the meaning of any commands that already work.  It is intended to
facilitate the addition of future VACUUM options that may take
non-Boolean parameters or that default to false.

Masahiko Sawada, reviewed by me.

Discussion: http://postgr.es/m/CA+TgmobpYrXr5sUaEe_T0boabV0DSm=utSOZzwCUNqfLEEm8Mw@mail.gmail.com
Discussion: http://postgr.es/m/CAD21AoBaFcKBAeL5_++j+Vzir2vBBcF4juW7qH8b3HsQY=Q6+w@mail.gmail.com
2019-03-29 08:22:49 -04:00
Robert Haas c900c15269 Warn more strongly about the dangers of exclusive backup mode.
Especially, warn about the hazards of mishandling the backup_label
file.  Adjust a couple of server messages to be more clear about
the hazards associated with removing backup_label files, too.

David Steele and Robert Haas, reviewed by Laurenz Albe, Martín
Marqués, Peter Eisentraut, and Magnus Hagander.

Discussion: http://postgr.es/m/7d85c387-000e-16f0-e00b-50bf83c22127@pgmasters.net
2019-03-29 08:15:16 -04:00
Peter Eisentraut bb76134b08 Fix incorrect code in new REINDEX CONCURRENTLY code
The previous code was adding pointers to transient variables to a
list, but by the time the list was read, the variable might be gone,
depending on the compiler.  Fix it by making copies in the proper
memory context.
2019-03-29 10:53:40 +01:00
Peter Eisentraut 5dc92b844e REINDEX CONCURRENTLY
This adds the CONCURRENTLY option to the REINDEX command.  A REINDEX
CONCURRENTLY on a specific index creates a new index (like CREATE
INDEX CONCURRENTLY), then renames the old index away and the new index
in place and adjusts the dependencies, and then drops the old
index (like DROP INDEX CONCURRENTLY).  The REINDEX command also has
the capability to run its other variants (TABLE, DATABASE) with the
CONCURRENTLY option (but not SYSTEM).

The reindexdb command gets the --concurrently option.

Author: Michael Paquier, Andreas Karlsson, Peter Eisentraut
Reviewed-by: Andres Freund, Fujii Masao, Jim Nasby, Sergei Kornilov
Discussion: https://www.postgresql.org/message-id/flat/60052986-956b-4478-45ed-8bd119e9b9cf%402ndquadrant.com#74948a1044c56c5e817a5050f554ddee
2019-03-29 08:26:33 +01:00
Andres Freund d25f519107 tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.
This moves the responsibility for:
- creating the storage necessary for a relation, including creating a
  new relfilenode for a relation with existing storage
- non-transactional truncation of a relation
- VACUUM FULL / CLUSTER's rewrite of a table
below tableam.

This is fairly straight forward, with a bit of complexity smattered in
to move the computation of xid / multixid horizons below the AM, as
they don't make sense for every table AM.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-28 20:01:43 -07:00
Thomas Munro 7e69323bf7 Fix typo.
Author: Masahiko Sawada
2019-03-29 10:03:58 +13:00
Tomas Vondra 62bf0fb35c Fix deserialization of pg_mcv_list values
There were multiple issues in deserialization of pg_mcv_list values.

Firstly, the data is loaded from syscache, but the deserialization was
performed after ReleaseSysCache(), at which point the data might have
already disappeared.  Fixed by moving the calls in statext_mcv_load,
and using the same NULL-handling code as existing stats.

Secondly, the deserialized representation used pointers into the
serialized representation.  But that is also unsafe, because the data
may disappear at any time.  Fixed by reworking and simplifying the
deserialization code to always copy all the data.

And thirdly, when deserializing values for types passed by value, the
code simply did memcpy(d,s,typlen) which however does not work on
bigendian machines.  Fixed by using fetch_att/store_att_byval.
2019-03-28 20:03:14 +01:00
Thomas Munro ad308058cc Use FullTransactionId for the transaction stack.
Provide GetTopFullTransactionId() and GetCurrentFullTransactionId().
The intended users of these interfaces are access methods that use
xids for visibility checks but don't want to have to go back and
"freeze" existing references some time later before the 32 bit xid
counter wraps around.

Use a new struct to serialize the transaction state for parallel
query, because FullTransactionId doesn't fit into the previous
serialization scheme very well.

Author: Thomas Munro
Reviewed-by: Heikki Linnakangas
Discussion: https://postgr.es/m/CAA4eK1%2BMv%2Bmb0HFfWM9Srtc6MVe160WFurXV68iAFMcagRZ0dQ%40mail.gmail.com
2019-03-28 18:24:43 +13:00
Thomas Munro 2fc7af5e96 Add basic infrastructure for 64 bit transaction IDs.
Instead of inferring epoch progress from xids and checkpoints,
introduce a 64 bit FullTransactionId type and use it to track xid
generation.  This fixes an unlikely bug where the epoch is reported
incorrectly if the range of active xids wraps around more than once
between checkpoints.

The only user-visible effect of this commit is to correct the epoch
used by txid_current() and txid_status(), also visible with
pg_controldata, in those rare circumstances.  It also creates some
basic infrastructure so that later patches can use 64 bit
transaction IDs in more places.

The new type is a struct that we pass by value, as a form of strong
typedef.  This prevents the sort of accidental confusion between
TransactionId and FullTransactionId that would be possible if we
were to use a plain old uint64.

Author: Thomas Munro
Reported-by: Amit Kapila
Reviewed-by: Andres Freund, Tom Lane, Heikki Linnakangas
Discussion: https://postgr.es/m/CAA4eK1%2BMv%2Bmb0HFfWM9Srtc6MVe160WFurXV68iAFMcagRZ0dQ%40mail.gmail.com
2019-03-28 18:12:20 +13:00
Andres Freund 2a96909a4a tableam: Support for an index build's initial table scan(s).
To support building indexes over tables of different AMs, the scans to
do so need to be routed through the table AM.  While moving a fair
amount of code, nearly all the changes are just moving code to below a
callback.

Currently the range based interface wouldn't make much sense for non
block based table AMs. But that seems aceptable for now.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-27 19:59:06 -07:00
Tomas Vondra a63b29a1de Minor improvements for the multivariate MCV lists
The MCV build should always call get_mincount_for_mcv_list(), as the
there is no other logic to decide whether the MCV list represents all
the data. So just remove the (ngroups > nitems) condition.

Also, when building MCV lists, the number of items was limited by the
statistics target (i.e. up to 10000). But when deserializing the MCV
list, a different value (8192) was used to check the input, causing
an error.  Simply ensure that the same value is used in both places.

This should have been included in 7300a69950, but I forgot to include it
in that commit.
2019-03-27 20:07:41 +01:00
Tomas Vondra 7300a69950 Add support for multivariate MCV lists
Introduce a third extended statistic type, supported by the CREATE
STATISTICS command - MCV lists, a generalization of the statistic
already built and used for individual columns.

Compared to the already supported types (n-distinct coefficients and
functional dependencies), MCV lists are more complex, include column
values and allow estimation of much wider range of common clauses
(equality and inequality conditions, IS NULL, IS NOT NULL etc.).
Similarly to the other types, a new pseudo-type (pg_mcv_list) is used.

Author: Tomas Vondra
Reviewed-by: Dean Rasheed, David Rowley, Mark Dilger, Alvaro Herrera
Discussion: https://postgr.es/m/dfdac334-9cf2-2597-fb27-f0fb3753f435@2ndquadrant.com
2019-03-27 18:32:18 +01:00
Tom Lane 333ed246c6 Avoid passing query tlist around separately from root->processed_tlist.
In the dim past, the planner kept the fully-processed version of the query
targetlist (the result of preprocess_targetlist) in grouping_planner's
local variable "tlist", and only grudgingly passed it to individual other
routines as needed.  Later we discovered a need to still have it available
after grouping_planner finishes, and invented the root->processed_tlist
field for that purpose, but it wasn't used internally to grouping_planner;
the tlist was still being passed around separately in the same places as
before.

Now comes a proposed patch to allow appendrel expansion to add entries
to the processed tlist, well after preprocess_targetlist has finished
its work.  To avoid having to pass around the tlist explicitly, it's
proposed to allow appendrel expansion to modify root->processed_tlist.
That makes aliasing the tlist with assorted parameters and local
variables really scary.  It would accidentally work as long as the
tlist is initially nonempty, because then the List header won't move
around, but it's not exactly hard to think of ways for that to break.
Aliased values are poor programming practice anyway.

Hence, get rid of local variables and parameters that can be identified
with root->processed_tlist, in favor of just using that field directly.
And adjust comments to match.  (Some of the new comments speak as though
it's already possible for appendrel expansion to modify the tlist; that's
not true yet, but will happen in a later patch.)

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp
2019-03-27 12:57:49 -04:00
Tom Lane a51cc7e9e6 Suppress uninitialized-variable warning.
Apparently Andres' compiler is smart enough to see that hpage
must be initialized before use ... but mine isn't.
2019-03-27 11:10:42 -04:00
Michael Paquier ecfed4a122 Improve error handling of column references in expression transformation
Column references are not allowed in default expressions and partition
bound expressions, and are restricted as such once the transformation of
their expressions is done.  However, trying to use more complex column
references can lead to confusing error messages.  For example, trying to
use a two-field column reference name for default expressions and
partition bounds leads to "missing FROM-clause entry for table", which
makes no sense in their respective context.

In order to make the errors generated more useful, this commit adds more
verbose messages when transforming column references depending on the
context.  This has a little consequence though: for example an
expression using an aggregate with a column reference as argument would
cause an error to be generated for the column reference, while the
aggregate was the problem reported before this commit because column
references get transformed first.

The confusion exists for default expressions for a long time, and the
problem is new as of v12 for partition bounds.  Still per the lack of
complaints on the matter no backpatch is done.

The patch has been written by Amit Langote and me, and Tom Lane has
provided the improvement of the documentation for default expressions on
the CREATE TABLE page.

Author: Amit Langote, Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20190326020853.GM2558@paquier.xyz
2019-03-27 21:04:25 +09:00
Thomas Munro d2fd7f74ee Fix off-by-one error in txid_status().
The transaction ID returned by GetNextXidAndEpoch() is in the future,
so we can't attempt to access its status or we might try to read a
CLOG page that doesn't exist.  The > vs >= confusion probably stemmed
from the choice of a variable name containing the word "last" instead
of "next", so fix that too.

Back-patch to 10 where the function arrived.

Author: Thomas Munro
Discussion: https://postgr.es/m/CA%2BhUKG%2Buua_BV5cyfsioKVN2d61Lukg28ECsWTXKvh%3DBtN2DPA%40mail.gmail.com
2019-03-27 21:30:04 +13:00
Michael Paquier 1983af8e89 Switch some palloc/memset calls to palloc0
Some code paths have been doing some allocations followed by an
immediate memset() to initialize the allocated area with zeros, this is
a bit overkill as there are already interfaces to do both things in one
call.

Author: Daniel Gustafsson
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/vN0OodBPkKs7g2Z1uyk3CUEmhdtspHgYCImhlmSxv1Xn6nY1ZnaaGHL8EWUIQ-NEv36tyc4G5-uA3UXUF2l4sFXtK_EQgLN1hcgunlFVKhA=@yesql.se
2019-03-27 12:02:50 +09:00
Tomas Vondra 6ca015f9f0 Track unowned relations in doubly-linked list
Relations dropped in a single transaction are tracked in a list of
unowned relations.  With large number of dropped relations this resulted
in poor performance at the end of a transaction, when the relations are
removed from the singly linked list one by one.

Commit b4166911 attempted to address this issue (particularly when it
happens during recovery) by removing the relations in a reverse order,
resulting in O(1) lookups in the list of unowned relations.  This did
not work reliably, though, and it was possible to trigger the O(N^2)
behavior in various ways.

Instead of trying to remove the relations in a specific order with
respect to the linked list, which seems rather fragile, switch to a
regular doubly linked.  That allows us to remove relations cheaply no
matter where in the list they are.

As b4166911 was a bugfix, backpatched to all supported versions, do the
same thing here.

Reviewed-by: Alvaro Herrera
Discussion: https://www.postgresql.org/message-id/flat/80c27103-99e4-1d0c-642c-d9f3b94aaa0a%402ndquadrant.com
Backpatch-through: 9.4
2019-03-27 02:39:39 +01:00
Andres Freund 558a9165e0 Compute XID horizon for page level index vacuum on primary.
Previously the xid horizon was only computed during WAL replay. That
had two major problems:
1) It relied on knowing what the table pointed to looks like. That was
   easy enough before the introducing of tableam (we knew it had to be
   heap, although some trickery around logging the heap relfilenodes
   was required). But to properly handle table AMs we need
   per-database catalog access to look up the AM handler, which
   recovery doesn't allow.
2) Not knowing the xid horizon also makes it hard to support logical
   decoding on standbys. When on a catalog table, we need to be able
   to conflict with slots that have an xid horizon that's too old. But
   computing the horizon by visiting the heap only works once
   consistency is reached, but we always need to be able to detect
   conflicts.

There's also a secondary problem, in that the current method performs
redundant work on every standby. But that's counterbalanced by
potentially computing the value when not necessary (either because
there's no standby, or because there's no connected backends).

Solve 1) and 2) by moving computation of the xid horizon to the
primary and by involving tableam in the computation of the horizon.

To address the potentially increased overhead, increase the efficiency
of the xid horizon computation for heap by sorting the tids, and
eliminating redundant buffer accesses. When prefetching is available,
additionally perform prefetching of buffers.  As this is more of a
maintenance task, rather than something routinely done in every read
only query, we add an arbitrary 10 to the effective concurrency -
thereby using IO concurrency, when not globally enabled.  That's
possibly not the perfect formula, but seems good enough for now.

Bumps WAL format, as latestRemovedXid is now part of the records, and
the heap's relfilenode isn't anymore.

Author: Andres Freund, Amit Khandekar, Robert Haas
Reviewed-By: Robert Haas
Discussion:
    https://postgr.es/m/20181212204154.nsxf3gzqv3gesl32@alap3.anarazel.de
    https://postgr.es/m/20181214014235.dal5ogljs3bmlq44@alap3.anarazel.de
    https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-26 16:52:54 -07:00
Alvaro Herrera 126d631222 Fix partitioned index creation bug with dropped columns
ALTER INDEX .. ATTACH PARTITION fails if the partitioned table where the
index is defined contains more dropped columns than its partition, with
this message:
  ERROR:  incorrect attribute map
The cause was that one caller of CompareIndexInfo was passing the number
of attributes of the partition rather than the parent, which confused
the length check.  Repair.

This can cause pg_upgrade to fail when used on such a database.  Leave
some more objects around after regression tests, so that the case is
detected by pg_upgrade test suite.

Remove some spurious empty lines noticed while looking for other cases
of the same problem.

Discussion: https://postgr.es/m/20190326213924.GA2322@alvherre.pgsql
2019-03-26 20:19:28 -03:00
Tom Lane 53bcf5e3db Build "other rels" of appendrel baserels in a separate step.
Up to now, otherrel RelOptInfos were built at the same time as baserel
RelOptInfos, thanks to recursion in build_simple_rel().  However,
nothing in query_planner's preprocessing cares at all about otherrels,
only baserels, so we don't really need to build them until just before
we enter make_one_rel.  This has two benefits:

* create_lateral_join_info did a lot of extra work to propagate
lateral-reference information from parents to the correct children.
But if we delay creation of the children till after that, it's
trivial (and much harder to break, too).

* Since we have all the restriction quals correctly assigned to
parent appendrels by this point, it'll be possible to do plan-time
pruning and never make child RelOptInfos at all for partitions that
can be pruned away.  That's not done here, but will be later on.

Amit Langote, reviewed at various times by Dilip Kumar, Jesper Pedersen,
Yoshikazu Imai, and David Rowley

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp
2019-03-26 18:21:10 -04:00
Tom Lane 7c366ac969 Fix oversight in data-type change for autovacuum_vacuum_cost_delay.
Commit caf626b2c missed that the relevant reloptions entry needs
to be moved from the intRelOpts[] array to realRelOpts[].
Somewhat surprisingly, it seems to work anyway, perhaps because
the desired default and limit values are all integers.  We ought
to have either a simpler data structure or better cross-checking
here, but that's for another patch.

Nikolay Shaplov

Discussion: https://postgr.es/m/4861742.12LTaSB3sv@x200m
2019-03-26 13:32:38 -04:00
Tom Lane e8d5dd6be7 Get rid of duplicate child RTE for a partitioned table.
We've been creating duplicate RTEs for partitioned tables just
because we do so for regular inheritance parent tables.  But unlike
regular-inheritance parents which are themselves regular tables
and thus need to be scanned, partitioned tables don't need the
extra RTE.

This makes the conditions for building a child RTE the same as those
for building an AppendRelInfo, allowing minor simplification in
expand_single_inheritance_child.  Since the planner's actual processing
is driven off the AppendRelInfo list, nothing much changes beyond that,
we just have one fewer useless RTE entry.

Amit Langote, reviewed and hacked a bit by me

Discussion: https://postgr.es/m/9d7c5112-cb99-6a47-d3be-cf1ee6862a1d@lab.ntt.co.jp
2019-03-26 12:03:27 -04:00