There are 2-arguments and 4-arguments versions of jsonb_path_match() and
jsonb_path_exists(). But 4-arguments versions have optional 3rd and 4th
arguments, that leads to ambiguity. In the same time 2-arguments versions are
needed only for @@ and @? operators. So, rename 2-arguments versions to
remove the ambiguity.
Catversion is bumped.
Aggregates have acquired a dozen or so optional attributes in recent
years for things like parallel query and moving-aggregate mode; the
lack of an OR REPLACE option to add or change these for an existing
agg makes extension upgrades gratuitously hard. Rectify.
SQL 2016 standards among other things contains set of SQL/JSON features for
JSON processing inside of relational database. The core of SQL/JSON is JSON
path language, allowing access parts of JSON documents and make computations
over them. This commit implements partial support JSON path language as
separate datatype called "jsonpath". The implementation is partial because
it's lacking datetime support and suppression of numeric errors. Missing
features will be added later by separate commits.
Support of SQL/JSON features requires implementation of separate nodes, and it
will be considered in subsequent patches. This commit includes following
set of plain functions, allowing to execute jsonpath over jsonb values:
* jsonb_path_exists(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_match(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_query(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_query_array(jsonb, jsonpath[, jsonb, bool]).
* jsonb_path_query_first(jsonb, jsonpath[, jsonb, bool]).
This commit also implements "jsonb @? jsonpath" and "jsonb @@ jsonpath", which
are wrappers over jsonpath_exists(jsonb, jsonpath) and jsonpath_predicate(jsonb,
jsonpath) correspondingly. These operators will have an index support
(implemented in subsequent patches).
Catversion bumped, to add new functions and operators.
Code was written by Nikita Glukhov and Teodor Sigaev, revised by me.
Documentation was written by Oleg Bartunov and Liudmila Mantrova. The work
was inspired by Oleg Bartunov.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Author: Nikita Glukhov, Teodor Sigaev, Alexander Korotkov, Oleg Bartunov, Liudmila Mantrova
Reviewed-by: Tomas Vondra, Andrew Dunstan, Pavel Stehule, Alexander Korotkov
The SQL:2016 standard adds support for the hyperbolic functions
sinh(), cosh(), and tanh(). POSIX has long required libm to
provide those functions as well as their inverses asinh(),
acosh(), atanh(). Hence, let's just expose the libm functions
to the SQL level. As with the trig functions, we only implement
versions for float8, not numeric.
For the moment, we'll assume that all platforms actually do have
these functions; if experience teaches otherwise, some autoconf
effort may be needed.
SQL:2016 also adds support for base-10 logarithm, but with the
function name log10(), whereas the name we've long used is log().
Add aliases named log10() for the float8 and numeric versions.
Lætitia Avrot
Discussion: https://postgr.es/m/CAB_COdguG22LO=rnxDQ2DW1uzv8aQoUzyDQNJjrR4k00XSgm5w@mail.gmail.com
In the v11-era commits that taught genbki.pl to resolve symbolic
OID references in the initial catalog data, we didn't bother to
make every last reference symbolic; some of the catalogs have so
few initial rows that it didn't seem worthwhile.
However, the new project policy that OIDs assigned by new patches
should be automatically renumberable changes this calculus.
A patch that wants to add a row in one of these catalogs would have
a problem when the OID it assigns gets renumbered. Hence, do the
mop-up work needed to make all OID references in initial data be
symbolic, and establish an associated project policy that we'll
never again write a hard-wired OID reference there.
No catversion bump since the contents of postgres.bki aren't
actually changed by this commit.
Discussion: https://postgr.es/m/CAH2-WzmMTGMcPuph4OvsO7Ykut0AOCF_i-=eaochT0dd2BN9CQ@mail.gmail.com
This commit adds a Perl script renumber_oids.pl, which can reassign a
range of manually-assigned OIDs to someplace else by modifying OID
fields of the catalog *.dat files and OID-assigning macros in the
catalog *.h files.
Up to now, we've encouraged new patches that need manually-assigned
OIDs to use OIDs just above the range of existing OIDs. Predictably,
this leads to patches stepping on each others' toes, as whichever
one gets committed first creates an OID conflict that other patch
author(s) have to resolve manually. With the availability of
renumber_oids.pl, we can eliminate a lot of this hassle.
The new project policy, therefore, is:
* Encourage new patches to use high OIDs (the documentation suggests
choosing a block of OIDs at random in 8000..9999).
* After feature freeze in each development cycle, run renumber_oids.pl
to move all such OIDs down to lower numbers, thus freeing the high OID
range for the next development cycle.
This plan should greatly reduce the risk of OID collisions between
concurrently-developed patches. Also, if such a collision happens
anyway, we have the option to resolve it without much effort by doing
an off-schedule OID renumbering to get the first-committed patch out
of the way. Or a patch author could use renumber_oids.pl to change
their patch's assignments without much pain.
This approach does put a premium on not hard-wiring any OID values
in places where renumber_oids.pl and genbki.pl can't fix them.
Project practice in that respect seems to be pretty good already,
but a follow-on patch will sand down some rough edges.
John Naylor and Tom Lane, per an idea of Peter Geoghegan's
Discussion: https://postgr.es/m/CAH2-WzmMTGMcPuph4OvsO7Ykut0AOCF_i-=eaochT0dd2BN9CQ@mail.gmail.com
Too allow table accesses to be not directly dependent on heap, several
new abstractions are needed. Specifically:
1) Heap scans need to be generalized into table scans. Do this by
introducing TableScanDesc, which will be the "base class" for
individual AMs. This contains the AM independent fields from
HeapScanDesc.
The previous heap_{beginscan,rescan,endscan} et al. have been
replaced with a table_ version.
There's no direct replacement for heap_getnext(), as that returned
a HeapTuple, which is undesirable for a other AMs. Instead there's
table_scan_getnextslot(). But note that heap_getnext() lives on,
it's still used widely to access catalog tables.
This is achieved by new scan_begin, scan_end, scan_rescan,
scan_getnextslot callbacks.
2) The portion of parallel scans that's shared between backends need
to be able to do so without the user doing per-AM work. To achieve
that new parallelscan_{estimate, initialize, reinitialize}
callbacks are introduced, which operate on a new
ParallelTableScanDesc, which again can be subclassed by AMs.
As it is likely that several AMs are going to be block oriented,
block oriented callbacks that can be shared between such AMs are
provided and used by heap. table_block_parallelscan_{estimate,
intiialize, reinitialize} as callbacks, and
table_block_parallelscan_{nextpage, init} for use in AMs. These
operate on a ParallelBlockTableScanDesc.
3) Index scans need to be able to access tables to return a tuple, and
there needs to be state across individual accesses to the heap to
store state like buffers. That's now handled by introducing a
sort-of-scan IndexFetchTable, which again is intended to be
subclassed by individual AMs (for heap IndexFetchHeap).
The relevant callbacks for an AM are index_fetch_{end, begin,
reset} to create the necessary state, and index_fetch_tuple to
retrieve an indexed tuple. Note that index_fetch_tuple
implementations need to be smarter than just blindly fetching the
tuples for AMs that have optimizations similar to heap's HOT - the
currently alive tuple in the update chain needs to be fetched if
appropriate.
Similar to table_scan_getnextslot(), it's undesirable to continue
to return HeapTuples. Thus index_fetch_heap (might want to rename
that later) now accepts a slot as an argument. Core code doesn't
have a lot of call sites performing index scans without going
through the systable_* API (in contrast to loads of heap_getnext
calls and working directly with HeapTuples).
Index scans now store the result of a search in
IndexScanDesc->xs_heaptid, rather than xs_ctup->t_self. As the
target is not generally a HeapTuple anymore that seems cleaner.
To be able to sensible adapt code to use the above, two further
callbacks have been introduced:
a) slot_callbacks returns a TupleTableSlotOps* suitable for creating
slots capable of holding a tuple of the AMs
type. table_slot_callbacks() and table_slot_create() are based
upon that, but have additional logic to deal with views, foreign
tables, etc.
While this change could have been done separately, nearly all the
call sites that needed to be adapted for the rest of this commit
also would have been needed to be adapted for
table_slot_callbacks(), making separation not worthwhile.
b) tuple_satisfies_snapshot checks whether the tuple in a slot is
currently visible according to a snapshot. That's required as a few
places now don't have a buffer + HeapTuple around, but a
slot (which in heap's case internally has that information).
Additionally a few infrastructure changes were needed:
I) SysScanDesc, as used by systable_{beginscan, getnext} et al. now
internally uses a slot to keep track of tuples. While
systable_getnext() still returns HeapTuples, and will so for the
foreseeable future, the index API (see 1) above) now only deals with
slots.
The remainder, and largest part, of this commit is then adjusting all
scans in postgres to use the new APIs.
Author: Andres Freund, Haribabu Kommi, Alvaro Herrera
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20160812231527.GA690404@alvherre.pgsql
This change makes it possible to specify sub-millisecond delays,
which work well on most modern platforms, though that was not true
when the cost-delay feature was designed.
To support this without breaking existing configuration entries,
improve guc.c to allow floating-point GUCs to have units. Also,
allow "us" (microseconds) as an input/output unit for time-unit GUCs.
(It's not allowed as a base unit, at least not yet.)
Likewise change the autovacuum_vacuum_cost_delay reloption to be
floating-point; this forces a catversion bump because the layout of
StdRdOptions changes.
This patch doesn't in itself change the default values or allowed
ranges for these parameters, and it should not affect the behavior
for any already-allowed setting for them.
Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us
This adds a column that counts how many checksum failures have occurred
on files belonging to a specific database. Both checksum failures
during normal backend processing and those created when a base backup
detects a checksum failure are counted.
Author: Magnus Hagander
Reviewed by: Julien Rouhaud
Use Getopt::Long in preference to hand-rolled option parsing code.
Also, remove "-I .../backend/catalog" switch from the Makefile
invocations. That's been unnecessary for some time, and leaving it
there gives the false impression it's needed in manual invocations.
John Naylor (extracted from a larger but more controversial patch)
Discussion: https://postgr.es/m/CACPNZCsHdcQN2jQ1=ptbi1Co2Nj3aHgRCUMk62=ThgWNabPY+Q@mail.gmail.com
Before commit 3fa2bb31 this type appeared in the catalogs to
select which of several block storage mechanisms each relation
used.
New features under development propose to revive the concept of
different block storage managers for new kinds of data accessed
via bufmgr.c, but don't need to put references to them in the
catalogs. So, avoid useless maintenance work on this type by
dropping it. Update some regression tests that were referencing
it where any type would do.
Discussion: https://postgr.es/m/CA%2BhUKG%2BDE0mmiBZMtZyvwWtgv1sZCniSVhXYsXkvJ_Wo%2B83vvw%40mail.gmail.com
This includes a catversion bump, as IntoClause is theoretically
speaking part of storable rules. In practice I don't think that can
happen, but there's no reason to be stingy here.
Per buildfarm member calliphoridae.
This introduces the concept of table access methods, i.e. CREATE
ACCESS METHOD ... TYPE TABLE and
CREATE TABLE ... USING (storage-engine).
No table access functionality is delegated to table AMs as of this
commit, that'll be done in following commits.
Subsequent commits will incrementally abstract table access
functionality to be routed through table access methods. That change
is too large to be reviewed & committed at once, so it'll be done
incrementally.
Docs will be updated at the end, as adding them incrementally would
likely make them less coherent, and definitely is a lot more work,
without a lot of benefit.
Table access methods are specified similar to index access methods,
i.e. pg_am.amhandler returns, as INTERNAL, a pointer to a struct with
callbacks. In contrast to index AMs that struct needs to live as long
as a backend, typically that's achieved by just returning a pointer to
a constant struct.
Psql's \d+ now displays a table's access method. That can be disabled
with HIDE_TABLEAM=true, which is mainly useful so regression tests can
be run against different AMs. It's quite possible that this behaviour
still needs to be fine tuned.
For now it's not allowed to set a table AM for a partitioned table, as
we've not resolved how partitions would inherit that. Disallowing
allows us to introduce, if we decide that's the way forward, such a
behaviour without a compatibility break.
Catversion bumped, to add the heap table AM and references to it.
Author: Haribabu Kommi, Andres Freund, Alvaro Herrera, Dimitri Golgov and others
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20160812231527.GA690404@alvherre.pgsqlhttps://postgr.es/m/20190107235616.6lur25ph22u5u5av@alap3.anarazel.dehttps://postgr.es/m/20190304234700.w5tmhducs5wxgzls@alap3.anarazel.de
This is similar in spirit to the existing partbounds.c file in the
same directory, except that there's a lot less code in the new file
created by this commit. Pending work in this area proposes to add a
bunch more code related to PartitionDescs, though, and this will give
us a good place to put it.
Discussion: http://postgr.es/m/CA+TgmoZUwPf_uanjF==gTGBMJrn8uCq52XYvAEorNkLrUdoawg@mail.gmail.com
pg_config() has been marked immutable since its inception. As part of a
larger discussion around the definition of immutable versus stable and
related implications for marking functions parallel safe raised by
Andres, the consensus was clearly that pg_config() is stable, since
it could possibly change output even for the same minor version with
a recompile or installation of a new binary. So mark it stable.
Theoretically this could/should be backpatched, but it was deemed to be not
worth the effort since in practice this is very unlikely to cause problems
in the real world.
Discussion: https://postgr.es/m/20181126234521.rh3grz7aavx2ubjv@alap3.anarazel.de
Historically we've always materialized the full output of a CTE query,
treating WITH as an optimization fence (so that, for example, restrictions
from the outer query cannot be pushed into it). This is appropriate when
the CTE query is INSERT/UPDATE/DELETE, or is recursive; but when the CTE
query is non-recursive and side-effect-free, there's no hazard of changing
the query results by pushing restrictions down.
Another argument for materialization is that it can avoid duplicate
computation of an expensive WITH query --- but that only applies if
the WITH query is called more than once in the outer query. Even then
it could still be a net loss, if each call has restrictions that
would allow just a small part of the WITH query to be computed.
Hence, let's change the behavior for WITH queries that are non-recursive
and side-effect-free. By default, we will inline them into the outer
query (removing the optimization fence) if they are called just once.
If they are called more than once, we will keep the old behavior by
default, but the user can override this and force inlining by specifying
NOT MATERIALIZED. Lastly, the user can force the old behavior by
specifying MATERIALIZED; this would mainly be useful when the query had
deliberately been employing WITH as an optimization fence to prevent a
poor choice of plan.
Andreas Karlsson, Andrew Gierth, David Fetter
Discussion: https://postgr.es/m/87sh48ffhb.fsf@news-spur.riddles.org.uk
For a long time, indxpath.c has had the ability to extract derived (lossy)
index conditions from certain operators such as LIKE. For just as long,
it's been obvious that we really ought to make that capability available
to extensions. This commit finally accomplishes that, by adding another
API for planner support functions that lets them create derived index
conditions for their functions. As proof of concept, the hardwired
"special index operator" code formerly present in indxpath.c is pushed
out to planner support functions attached to LIKE and other relevant
operators.
A weak spot in this design is that an extension needs to know OIDs for
the operators, datatypes, and opfamilies involved in the transformation
it wants to make. The core-code prototypes use hard-wired OID references
but extensions don't have that option for their own operators etc. It's
usually possible to look up the required info, but that may be slow and
inconvenient. However, improving that situation is a separate task.
I want to do some additional refactorization around selfuncs.c, but
that also seems like a separate task.
Discussion: https://postgr.es/m/15193.1548028093@sss.pgh.pa.us
Since its introduction, max_wal_senders is counted as part of
max_connections when it comes to define how many connection slots can be
used for replication connections with a WAL sender context. This can
lead to confusion for some users, as it could be possible to block a
base backup or replication from happening because other backend sessions
are already taken for other purposes by an application, and
superuser-only connection slots are not a correct solution to handle
that case.
This commit makes max_wal_senders independent of max_connections for its
handling of PGPROC entries in ProcGlobal, meaning that connection slots
for WAL senders are handled using their own free queue, like autovacuum
workers and bgworkers.
One compatibility issue that this change creates is that a standby now
requires to have a value of max_wal_senders at least equal to its
primary. So, if a standby created enforces the value of
max_wal_senders to be lower than that, then this could break failovers.
Normally this should not be an issue though, as any settings of a
standby are inherited from its primary as postgresql.conf gets normally
copied as part of a base backup, so parameters would be consistent.
Author: Alexander Kukushkin
Reviewed-by: Kyotaro Horiguchi, Petr Jelínek, Masahiko Sawada, Oleksii
Kliukin
Discussion: https://postgr.es/m/CAFh8B=nBzHQeYAu0b8fjK-AF1X4+_p6GRtwG+cCgs6Vci2uRuQ@mail.gmail.com
The original setup for dependencies of partitioned objects had
serious problems:
1. It did not verify that a drop cascading to a partition-child object
also cascaded to at least one of the object's partition parents. Now,
normally a child object would share all its dependencies with one or
another parent (e.g. a child index's opclass dependencies would be shared
with the parent index), so that this oversight is usually harmless.
But if some dependency failed to fit this pattern, the child could be
dropped while all its parents remain, creating a logically broken
situation. (It's easy to construct artificial cases that break it,
such as attaching an unrelated extension dependency to the child object
and then dropping the extension. I'm not sure if any less-artificial
cases exist.)
2. Management of partition dependencies during ATTACH/DETACH PARTITION
was complicated and buggy; for example, after detaching a partition
table it was possible to create cases where a formerly-child index
should be dropped and was not, because the correct set of dependencies
had not been reconstructed.
Less seriously, because multiple partition relationships were
represented identically in pg_depend, there was an order-of-traversal
dependency on which partition parent was cited in error messages.
We also had some pre-existing order-of-traversal hazards for error
messages related to internal and extension dependencies. This is
cosmetic to users but causes testing problems.
To fix#1, add a check at the end of the partition tree traversal
to ensure that at least one partition parent got deleted. To fix#2,
establish a new policy that partition dependencies are in addition to,
not instead of, a child object's usual dependencies; in this way
ATTACH/DETACH PARTITION need not cope with adding or removing the
usual dependencies.
To fix the cosmetic problem, distinguish between primary and secondary
partition dependency entries in pg_depend, by giving them different
deptypes. (They behave identically except for having different
priorities for being cited in error messages.) This means that the
former 'I' dependency type is replaced with new 'P' and 'S' types.
This also fixes a longstanding bug that after handling an internal
dependency by recursing to the owning object, findDependentObjects
did not verify that the current target was now scheduled for deletion,
and did not apply the current recursion level's objflags to it.
Perhaps that should be back-patched; but in the back branches it
would only matter if some concurrent transaction had removed the
internal-linkage pg_depend entry before the recursive call found it,
or the recursive call somehow failed to find it, both of which seem
unlikely.
Catversion bump because the contents of pg_depend change for
partitioning relationships.
Patch HEAD only. It's annoying that we're not fixing #2 in v11,
but there seems no practical way to do so given that the problem
is exactly a poor choice of what entries to put in pg_depend.
We can't really fix that while staying compatible with what's
in pg_depend in existing v11 installations.
Discussion: https://postgr.es/m/CAH2-Wzkypv1R+teZrr71U23J578NnTBt2X8+Y=Odr4pOdW1rXg@mail.gmail.com
Add support function requests for estimating the selectivity, cost,
and number of result rows (if a SRF) of the target function.
The lack of a way to estimate selectivity of a boolean-returning
function in WHERE has been a recognized deficiency of the planner
since Berkeley days. This commit finally fixes it.
In addition, non-constant estimates of cost and number of output
rows are now possible. We still fall back to looking at procost
and prorows if the support function doesn't service the request,
of course.
To make concrete use of the possibility of estimating output rowcount
for SRFs, this commit adds support functions for array_unnest(anyarray)
and the integer variants of generate_series; the lack of plausible
rowcount estimates for those, even when it's obvious to a human,
has been a repeated subject of complaints. Obviously, much more
could now be done in this line, but I'm mostly just trying to get
the infrastructure in place.
Discussion: https://postgr.es/m/15193.1548028093@sss.pgh.pa.us
Rename/repurpose pg_proc.protransform as "prosupport". The idea is
still that it names an internal function that provides knowledge to
the planner about the behavior of the function it's attached to;
but redesign the API specification so that it's not limited to doing
just one thing, but can support an extensible set of requests.
The original purpose of simplifying a function call is handled by
the first request type to be invented, SupportRequestSimplify.
Adjust all the existing transform functions to handle this API,
and rename them fron "xxx_transform" to "xxx_support" to reflect
the potential generalization of what they do. (Since we never
previously provided any way for extensions to add transform functions,
this change doesn't create an API break for them.)
Also add DDL and pg_dump support for attaching a support function to a
user-defined function. Unfortunately, DDL access has to be restricted
to superusers, at least for now; but seeing that support functions
will pretty much have to be written in C, that limitation is just
theoretical. (This support is untested in this patch, but a follow-on
patch will add cases that exercise it.)
Discussion: https://postgr.es/m/15193.1548028093@sss.pgh.pa.us
This is useful when looking at partition trees with multiple layers, and
combined with pg_partition_tree, it provides the possibility to show up
an entire tree by just knowing one member at any level.
Author: Michael Paquier
Reviewed-by: Álvaro Herrera, Amit Langote
Discussion: https://postgr.es/m/20181207014015.GP2407@paquier.xyz
We can't allow these pseudo-types to be used as table column types,
because storing an anonymous record value in a table would result
in data that couldn't be understood by other sessions. However,
it seems like there's no harm in allowing the case in a column
definition list that's specifying what a function-returning-record
returns. The data involved is all local to the current session,
so we should be just as able to resolve its actual tuple type as
we are for the function-returning-record's top-level tuple output.
Elvis Pranskevichus, with cosmetic changes by me
Discussion: https://postgr.es/m/11038447.kQ5A9Uj5xi@hammer.magicstack.net
My commit 3de241dba8 introduced some code to create a clone of a
foreign key to a partition, but I put it in pg_constraint.c because it
was too close to the contents of the pg_constraint row. With the
previous commit that split out the constraint tuple deconstruction into
its own routine, it makes more sense to have the FK-cloning function in
tablecmds.c, mostly because its static subroutine can then be used by a
future bugfix.
My initial posting of this patch had this routine as static in
tablecmds.c, but sadly this function is already part of the Postgres 11
ABI as exported from pg_constraint.c, so keep it as exported also just
to avoid breaking any possible users of it.
My commit 3de241dba8 introduced some code (in tablecmds.c) to obtain
data from a pg_constraint row for a foreign key, that already existed in
ri_triggers.c. Split it out into its own routine in pg_constraint.c,
where it naturally belongs.
No functional code changes, only code movement.
Backpatch to pg11, because a future bugfix is simpler after this.
heapam.h previously was included in a number of widely used
headers (e.g. execnodes.h, indirectly in executor.h, ...). That's
problematic on its own, as heapam.h contains a lot of low-level
details that don't need to be exposed that widely, but becomes more
problematic with the upcoming introduction of pluggable table storage
- it seems inappropriate for heapam.h to be included that widely
afterwards.
heapam.h was largely only included in other headers to get the
HeapScanDesc typedef (which was defined in heapam.h, even though
HeapScanDescData is defined in relscan.h). The better solution here
seems to be to just use the underlying struct (forward declared where
necessary). Similar for BulkInsertState.
Another problem was that LockTupleMode was used in executor.h - parts
of the file tried to cope without heapam.h, but due to the fact that
it indirectly included it, several subsequent violations of that goal
were not not noticed. We could just reuse the approach of declaring
parameters as int, but it seems nicer to move LockTupleMode to
lockoptions.h - that's not a perfect location, but also doesn't seem
bad.
As a number of files relied on implicitly included heapam.h, a
significant number of files grew an explicit include. It's quite
probably that a few external projects will need to do the same.
Author: Andres Freund
Reviewed-By: Alvaro Herrera
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
Some relation kinds had relfilenode set to some non-zero value, but
apparently the actual files did not really exist because creation was
prevented elsewhere. Get rid of the phony pg_class.relfilenode values.
Catversion bumped, but only because the sanity_test check will fail if
run in a system initdb'd with the previous version.
Reviewed-by: Kyotaro HORIGUCHI, Michael Paquier
Discussion: https://postgr.es/m/20181206215552.fm2ypuxq6nhpwjuc@alvherre.pgsql
Instead of running a SQL script to create the standard conversion
functions and pg_conversion entries, put those entries into the
initial data in postgres.bki.
This shaves a few percent off the runtime of initdb, and also allows
accurate comments to be attached to the conversion functions; the
previous script labeled them with machine-generated comments that
were not quite right for multi-purpose conversion functions.
Also, we can get rid of the duplicative Makefile and MSVC perl
implementations of the generation code for that SQL script.
A functional change is that these pg_proc and pg_conversion entries
are now "pinned" by initdb. Leaving them unpinned was perhaps a
good thing back while the conversions feature was under development,
but there seems no valid reason for it now.
Also, the conversion functions are now marked as immutable, where
before they were volatile by virtue of lacking any explicit
specification. That seems like it was just an oversight.
To avoid using magic constants in pg_conversion.dat, extend
genbki.pl to allow encoding names to be converted, much as it
does for language, access method, etc names.
John Naylor
Discussion: https://postgr.es/m/CAJVSVGWtUqxpfAaxS88vEGvi+jKzWZb2EStu5io-UPc4p9rSJg@mail.gmail.com
This patch teaches genbki.pl to replace pg_language names by OIDs
in much the same way as it already does for pg_am names etc, and
converts pg_proc.dat to use such symbolic references in the prolang
column.
Aside from getting rid of a few more magic numbers in the initial
catalog data, this means that Gen_fmgrtab.pl no longer needs to read
pg_language.dat, since it doesn't have to know the OID of the "internal"
language; now it's just looking for the string "internal".
No need for a catversion bump, since the contents of postgres.bki
don't actually change at all.
John Naylor
Discussion: https://postgr.es/m/CAJVSVGWtUqxpfAaxS88vEGvi+jKzWZb2EStu5io-UPc4p9rSJg@mail.gmail.com
Mark pg_lsn and oidvector comparison functions as leakproof. Per
discussion, these clearly are leakproof so we might as well mark them so.
On the other hand, remove leakproof markings from name comparison
functions other than equal/not-equal. Now that these depend on
varstr_cmp, they can't be considered leakproof if text comparison isn't.
(This was my error in commit 586b98fdf.)
While at it, add some opr_sanity queries to catch cases where related
functions do not have the same volatility and leakproof markings.
This would clearly be bogus for commutator or negator pairs. In the
domain of btree comparison functions, we do have some exceptions,
because text equality is leakproof but inequality comparisons are not.
That's odd on first glance but is reasonable (for now anyway) given
the much greater complexity of the inequality code paths.
Discussion: https://postgr.es/m/20181231172551.GA206480@gust.leadboat.com
Up to now we've not worried much about joins where the join key is a
relation's CTID column, reasoning that storing a table's CTIDs in some
other table would be pretty useless. However, there are use-cases for
this sort of query involving self-joins, so that argument doesn't really
hold water.
With larger relations, a merge or hash join is desirable. We had a btree
opclass for type "tid", allowing merge joins on CTID, but no hash opclass
so that hash joins weren't possible. Add the missing infrastructure.
This also potentially enables hash aggregation on "tid", though the
use-cases for that aren't too clear.
Discussion: https://postgr.es/m/1853.1545453106@sss.pgh.pa.us
The SQL spec says that sql_identifier is a domain over varchar,
but it also says that that domain is supposed to represent the set
of valid identifiers for the implementation, in particular applying
a length limit matching the implementation's identifier length limit.
We were declaring sql_identifier as just "character varying", thus
duplicating what the spec says about base type, but entirely failing
at the rest of it.
Instead, let's declare sql_identifier as a domain over type "name".
(We can drop the COLLATE "C" added by commit 6b0faf723, since that's
now implicit in "name".) With the recent improvements to name's
comparison support, there's not a lot of functional difference between
name and varchar. So although in principle this is a spec deviation,
it's a pretty minor one. And correctly enforcing PG's name length limit
is a good thing; on balance this seems closer to the intent of the spec
than what we had.
But that's all just language-lawyering. The *real* reason to do this is
that it makes sql_identifier columns exposed by information_schema views
be just direct representations of the underlying "name" catalog columns,
eliminating a semantic mismatch that was disastrous for performance of
typical queries on the information_schema. In combination with the
recent change to allow dropping no-op CoerceToDomain nodes, this allows
(for example) queries such as
select ... from information_schema.tables where table_name = 'foo';
to produce an indexscan rather than a seqscan on pg_class.
Discussion: https://postgr.es/m/CAFj8pRBUCX4LZ2rA2BbEkdD6NN59mgx+BLo1gO08Wod4RLtcTg@mail.gmail.com
information_schema output columns that are declared as being type
sql_identifier are supposed to conform to the implementation's rules
for valid identifiers, in particular the identifier length limit.
Several places potentially violated this limit by concatenating a
function's name and OID. (The OID is added to ensure name uniqueness
within a schema, since the spec doesn't expect function name overloading.)
Simply truncating the concatenation result to fit in "name" won't do,
since losing part of the OID might wind up giving non-unique results.
Instead, let's truncate the function name as necessary.
The most practical way to do that is to do it in a C function; the
information_schema.sql script doesn't have easy access to the value
of NAMEDATALEN, nor does it have an easy way to truncate on the basis
of resulting byte-length rather than number of characters.
(There are still a couple of places that cast concatenation results to
sql_identifier, but as far as I can see they are guaranteed not to produce
over-length strings, at least with the normal value of NAMEDATALEN.)
Discussion: https://postgr.es/m/23817.1545283477@sss.pgh.pa.us
Now that name comparison has effectively the same behavior as text
comparison, we might as well merge the name_ops opfamily into text_ops,
allowing cross-type comparisons to be processed without forcing a
datatype coercion first. We need do little more than add cross-type
operators to make the opfamily complete, and fix one or two places
in the planner that assumed text_ops was a single-datatype opfamily.
I chose to unify hash name_ops into hash text_ops as well, since the
types have compatible hashing semantics. This allows marking the
new cross-type equality operators as oprcanhash.
(Note: this doesn't remove the name_ops opclasses, so there's no
breakage of index definitions. Those opclasses are just reparented
into the text_ops opfamily.)
Discussion: https://postgr.es/m/15938.1544377821@sss.pgh.pa.us
The "name" comparison operators now all support collations, making them
functionally equivalent to "text" comparisons, except for the different
physical representation of the datatype. They do, in fact, mostly share
the varstr_cmp and varstr_sortsupport infrastructure, which has been
slightly enlarged to handle the case.
To avoid changes in the default behavior of the datatype, set name's
typcollation to C_COLLATION_OID not DEFAULT_COLLATION_OID, so that
by default comparisons to a name value will continue to use strcmp
semantics. (This would have been the case for system catalog columns
anyway, because of commit 6b0faf723, but doing this makes it true for
user-created name columns as well. In particular, this avoids
locale-dependent changes in our regression test results.)
In consequence, tweak a couple of places that made assumptions about
collatable base types always having typcollation DEFAULT_COLLATION_OID.
I have not, however, attempted to relax the restriction that user-
defined collatable types must have that. Hence, "name" doesn't
behave quite like a user-defined type; it acts more like a domain
with COLLATE "C". (Conceivably, if we ever get rid of the need for
catalog name columns to be fixed-length, "name" could actually become
such a domain over text. But that'd be a pretty massive undertaking,
and I'm not volunteering.)
Discussion: https://postgr.es/m/15938.1544377821@sss.pgh.pa.us
Up to now we allowed text columns in system catalogs to use collation
"default", but that isn't really safe because it might mean something
different in template0 than it means in a database cloned from template0.
In particular, this could mean that cloned pg_statistic entries for such
columns weren't entirely valid, possibly leading to bogus planner
estimates, though (probably) not any outright failures.
In the wake of commit 5e0928005, a better solution is available: if we
label such columns with "C" collation, then their pg_statistic entries
will also use that collation and hence will be valid independently of
the database collation.
This also provides a cleaner solution for indexes on such columns than
the hack added by commit 0b28ea79c: the indexes will naturally inherit
"C" collation and don't have to be forced to use text_pattern_ops.
Also, with the planned improvement of type "name" to be collation-aware,
this policy will apply cleanly to both text and name columns.
Because of the pg_statistic angle, we should also apply this policy
to the tables in information_schema. This patch does that by adjusting
information_schema's textual domain types to specify "C" collation.
That has the user-visible effect that order-sensitive comparisons to
textual information_schema view columns will now use "C" collation
by default. The SQL standard says that the collation of those view
columns is implementation-defined, so I think this is legal per spec.
At some point this might allow for translation of such comparisons
into indexable conditions on the underlying "name" columns, although
additional work will be needed before that can happen.
Discussion: https://postgr.es/m/19346.1544895309@sss.pgh.pa.us
When partitioned tables were introduced, we failed to realize that by
copying the tablespace handling for other relation kinds with no
physical storage we were causing the secondary effect that their
partitions would not automatically inherit the tablespace setting. This
is surprising and unhelpful, so change it to adopt the behavior
introduced in pg11 (commit 33e6c34c32) for partitioned indexes: the
parent relation remembers the tablespace specification, which is then
used for any new partitions that don't declare one.
Because this commit changes behavior of the TABLESPACE clause for
partitioned tables (it's no longer a no-op), it is not backpatched.
Author: David Rowley, Álvaro Herrera
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CAKJS1f9SxVzqDrGD1teosFd6jBMM0UEaa14_8mRvcWE19Tu0hA@mail.gmail.com
When we first put in collations support, we basically punted on teaching
pg_statistic, ANALYZE, and the planner selectivity functions about that.
They've just used DEFAULT_COLLATION_OID independently of the actual
collation of the data. It's time to improve that, so:
* Add columns to pg_statistic that record the specific collation associated
with each statistics slot.
* Teach ANALYZE to use the column's actual collation when comparing values
for statistical purposes, and record this in the appropriate slot. (Note
that type-specific typanalyze functions are now expected to fill
stats->stacoll with the appropriate collation, too.)
* Teach assorted selectivity functions to use the actual collation of
the stats they are looking at, instead of just assuming it's
DEFAULT_COLLATION_OID.
This should give noticeably better results in selectivity estimates for
columns with nondefault collations, at least for query clauses that use
that same collation (which would be the default behavior in most cases).
It's still true that comparisons with explicit COLLATE clauses different
from the stored data's collation won't be well-estimated, but that's no
worse than before. Also, this patch does make the first step towards
doing better with that, which is that it's now theoretically possible to
collect stats for a collation other than the column's own collation.
Patch by me; thanks to Peter Eisentraut for review.
Discussion: https://postgr.es/m/14706.1544630227@sss.pgh.pa.us
The changes I made in 578b229718 assigned oids below
FirstBootstrapObjectId to objects in include/catalog/*.dat files that
did not have an oid assigned, starting at the max oid explicitly
assigned. Tom criticized that for mainly two reasons:
1) It's not clear which values are manually and which explicitly
assigned.
2) The space below FirstBootstrapObjectId gets pretty crowded, and
some PostgreSQL forks have used oids >= 9000 for their own objects,
to avoid conflicting.
Thus create a new range for objects not assigned explicit oids, but
assigned by genbki.pl. For now 1-9999 is for explicitly assigned oids,
FirstGenbkiObjectId (10000) to FirstBootstrapObjectId (1200) -1 is for
genbki.pl assigned oids, and < FirstNormalObjectId (16384) is for oids
assigned during bootstrap. It's possible that we'll have to adjust
these boundaries, but there's some headroom for now.
Add a note suggesting that oids in forks should be assigned in the
9000-9999 range.
Catversion bump for obvious reasons.
Per complaint from Tom Lane.
Author: Andres Freund
Discussion: https://postgr.es/m/16845.1544393682@sss.pgh.pa.us
The timestamp generated by the standby at message transmission has been
included in the protocol since its introduction for both the status
update message and hot standby feedback message, but it has never
appeared in pg_stat_replication. Seeing this timestamp does not matter
much with a cluster which has a lot of activity, but on a mostly-idle
cluster, this makes monitoring able to react faster than the configured
timeouts.
Author: MyungKyu LIM
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/1657809367.407321.1533027417725.JavaMail.jboss@ep2ml404
