This feature has been a thorn in our sides for a long time, causing
many grammatical ambiguity problems. It doesn't seem worth the
pain to continue to support it, so remove it.
There are some follow-on improvements we can make in the grammar,
but this commit only removes the bare minimum number of productions,
plus assorted backend support code.
Note that pg_dump and psql continue to have full support, since
they may be used against older servers. However, pg_dump warns
about postfix operators. There is also a check in pg_upgrade.
Documentation-wise, I (tgl) largely removed the "left unary"
terminology in favor of saying "prefix operator", which is
a more standard and IMO less confusing term.
I included a catversion bump, although no initial catalog data
changes here, to mark the boundary at which oprkind = 'r'
stopped being valid in pg_operator.
Mark Dilger, based on work by myself and Robert Haas;
review by John Naylor
Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
Invent the concept of a B-Tree equalimage ("equality implies image
equality") support function, registered as support function 4. This
indicates whether it is safe (or not safe) to apply optimizations that
assume that any two datums considered equal by an operator class's order
method must be interchangeable without any loss of semantic information.
This is static information about an operator class and a collation.
Register an equalimage routine for almost all of the existing B-Tree
opclasses. We only need two trivial routines for all of the opclasses
that are included with the core distribution. There is one routine for
opclasses that index non-collatable types (which returns 'true'
unconditionally), plus another routine for collatable types (which
returns 'true' when the collation is a deterministic collation).
This patch is infrastructure for an upcoming patch that adds B-Tree
deduplication.
Author: Peter Geoghegan, Anastasia Lubennikova
Discussion: https://postgr.es/m/CAH2-Wzn3Ee49Gmxb7V1VJ3-AC8fWn-Fr8pfWQebHe8rYRxt5OQ@mail.gmail.com
Historically, the term procedure was used as a synonym for function in
Postgres/PostgreSQL. Now we have procedures as separate objects from
functions, so we need to clean up the documentation to not mix those
terms.
In particular, mentions of "trigger procedures" are changed to "trigger
functions", and access method "support procedures" are changed to
"support functions". (The latter already used FUNCTION in the SQL
syntax anyway.) Also, the terminology in the SPI chapter has been
cleaned up.
A few tests, examples, and code comments are also adjusted to be
consistent with documentation changes, but not everything.
Reported-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
Since some preparation work had already been done, the only source
changes left were changing empty-element tags like <xref linkend="foo">
to <xref linkend="foo"/>, and changing the DOCTYPE.
The source files are still named *.sgml, but they are actually XML files
now. Renaming could be considered later.
In the build system, the intermediate step to convert from SGML to XML
is removed. Everything is build straight from the source files again.
The OpenSP (or the old SP) package is no longer needed.
The documentation toolchain instructions are updated and are much
simpler now.
Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
IDs in SGML are case insensitive, and we have accumulated a mix of upper
and lower case IDs, including different variants of the same ID. In
XML, these will be case sensitive, so we need to fix up those
differences. Going to all lower case seems most straightforward, and
the current build process already makes all anchors and lower case
anyway during the SGML->XML conversion, so this doesn't create any
difference in the output right now. A future XML-only build process
would, however, maintain any mixed case ID spellings in the output, so
that is another reason to clean this up beforehand.
Author: Alexander Lakhin <exclusion@gmail.com>
For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name. Add a warning option to catch future
occurrences.
Alexander Lakhin, Jürgen Purtz
We had thirty different GIN array opclasses sharing the same operators and
support functions. That still didn't cover all the built-in types, nor
did it cover arrays of extension-added types. What we want is a single
polymorphic opclass for "anyarray". There were two missing features needed
to make this possible:
1. We have to be able to declare the index storage type as ANYELEMENT
when the opclass is declared to index ANYARRAY. This just takes a few
more lines in index_create(). Although this currently seems of use only
for GIN, there's no reason to make index_create() restrict it to that.
2. We have to be able to identify the proper GIN compare function for
the index storage type. This patch proceeds by making the compare function
optional in GIN opclass definitions, and specifying that the default btree
comparison function for the index storage type will be looked up when the
opclass omits it. Again, that seems pretty generically useful.
Since the comparison function lookup is done in initGinState(), making
use of the second feature adds an additional cache lookup to GIN index
access setup. It seems unlikely that that would be very noticeable given
the other costs involved, but maybe at some point we should consider
making GinState data persist longer than it now does --- we could keep it
in the index relcache entry, perhaps.
Rather fortuitously, we don't seem to need to do anything to get this
change to play nice with dump/reload or pg_upgrade scenarios: the new
opclass definition is automatically selected to replace existing index
definitions, and the on-disk data remains compatible. Also, if a user has
created a custom opclass definition for a non-builtin type, this doesn't
break that, since CREATE INDEX will prefer an exact match to opcintype
over a match to ANYARRAY. However, if there's anyone out there with
handwritten DDL that explicitly specifies _bool_ops or one of the other
replaced opclass names, they'll need to adjust that.
Tom Lane, reviewed by Enrique Meneses
Discussion: <14436.1470940379@sss.pgh.pa.us>
The chapter "Interfacing Extensions To Indexes" and CREATE OPERATOR
CLASS reference page were missed when BRIN was added. We document
all our other index access methods there, so make sure BRIN complies.
Author: Álvaro Herrera
Reported-By: Julien Rouhaud, Tom Lane
Reviewed-By: Emre Hasegeli
Discussion: https://www.postgresql.org/message-id/56CF604E.9000303%40dalibo.com
Backpatch: 9.5, where BRIN was introduced
The conventions specified by the GiST SGML documentation were widely
ignored. For example, the strategy-number argument for "consistent" and
"distance" functions is specified to be a smallint, but most of the
built-in support functions declared it as an integer, and for that matter
the core code passed it using Int32GetDatum not Int16GetDatum. None of
that makes any real difference at runtime, but it's quite confusing for
newcomers to the code, and it makes it very hard to write an amvalidate()
function that checks support function signatures. So let's try to instill
some consistency here.
Another similar issue is that the "query" argument is not of a single
well-defined type, but could have different types depending on the strategy
(corresponding to search operators with different righthand-side argument
types). Some of the functions threw up their hands and declared the query
argument as being of "internal" type, which surely isn't right ("any" would
have been more appropriate); but the majority position seemed to be to
declare it as being of the indexed data type, corresponding to a search
operator with both input types the same. So I've specified a convention
that that's what to do always.
Also, the result of the "union" support function actually must be of the
index's storage type, but the documentation suggested declaring it to
return "internal", and some of the functions followed that. Standardize
on telling the truth, instead.
Similarly, standardize on declaring the "same" function's inputs as
being of the storage type, not "internal".
Also, somebody had forgotten to add the "recheck" argument to both
the documentation of the "distance" support function and all of their
SQL declarations, even though the C code was happily using that argument.
Clean that up too.
Fix up some other omissions in the docs too, such as documenting that
union's second input argument is vestigial.
So far as the errors in core function declarations go, we can just fix
pg_proc.h and bump catversion. Adjusting the erroneous declarations in
contrib modules is more debatable: in principle any change in those
scripts should involve an extension version bump, which is a pain.
However, since these changes are purely cosmetic and make no functional
difference, I think we can get away without doing that.
DocBook XML is superficially compatible with DocBook SGML but has a
slightly stricter DTD that we have been violating in a few cases.
Although XSLT doesn't care whether the document is valid, the style
sheets don't necessarily process invalid documents correctly, so we need
to work toward fixing this.
This first commit moves the indexterms in refentry elements to an
allowed position. It has no impact on the output.
SP-GiST is comparable to GiST in flexibility, but supports non-balanced
partitioned search structures rather than balanced trees. As described at
PGCon 2011, this new indexing structure can beat GiST in both index build
time and query speed for search problems that it is well matched to.
There are a number of areas that could still use improvement, but at this
point the code seems committable.
Teodor Sigaev and Oleg Bartunov, with considerable revisions by Tom Lane
This patch creates an API whereby a btree index opclass can optionally
provide non-SQL-callable support functions for sorting. In the initial
patch, we only use this to provide a directly-callable comparator function,
which can be invoked with a bit less overhead than the traditional
SQL-callable comparator. While that should be of value in itself, the real
reason for doing this is to provide a datatype-extensible framework for
more aggressive optimizations, as in Peter Geoghegan's recent work.
Robert Haas and Tom Lane
This commit adds columns amoppurpose and amopsortfamily to pg_amop, and
column amcanorderbyop to pg_am. For the moment all the entries in
amcanorderbyop are "false", since the underlying support isn't there yet.
Also, extend the CREATE OPERATOR CLASS/ALTER OPERATOR FAMILY commands with
[ FOR SEARCH | FOR ORDER BY sort_operator_family ] clauses to allow the new
columns of pg_amop to be populated, and create pg_dump support for dumping
that information.
I also added some documentation, although it's perhaps a bit premature
given that the feature doesn't do anything useful yet.
Teodor Sigaev, Robert Haas, Tom Lane
The endterm attribute is mainly useful when the toolchain does not support
automatic link target text generation for a particular situation. In the
past, this was required by the man page tools for all reference page links,
but that is no longer the case, and it now actually gets in the way of
proper automatic link text generation. The only remaining use cases are
currently xrefs to refsects.
another section if required by the platform (instead of the old way of
building them in section "l" and always transforming them to the
platform-specific section).
This speeds up the installation on common platforms, and it avoids some
funny business with the man page tools and build process.
"consistent" functions, and remove pg_amop.opreqcheck, as per recent
discussion. The main immediate benefit of this is that we no longer need
8.3's ugly hack of requiring @@@ rather than @@ to test weight-using tsquery
searches on GIN indexes. In future it should be possible to optimize some
other queries better than is done now, by detecting at runtime whether the
index match is exact or not.
Tom Lane, after an idea of Heikki's, and with some help from Teodor.
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
FAMILY; and add FAMILY option to CREATE OPERATOR CLASS to allow adding a
class to a pre-existing family. Per previous discussion. Man, what a
tedious lot of cutting and pasting ...
permissions on the functions and operators contained in the opclass.
Since we already require superuser privilege to create an operator class,
there's no expansion-of-privilege hazard here, but if someone were to get
the idea of building an opclass containing functions that need security
restrictions, we'd better warn them off. Also, change the permission
checks from have-execute-privilege to have-ownership, and then comment
them all out since they're dead code anyway under the superuser restriction.
including:
- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on
- fix an omission in the EXECUTE documentation
- add some more text to the EXPLAIN documentation
- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)
- minor markup fixes
Neil Conway
with OPAQUE, as per recent pghackers discussion. I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...
documentation (xindex.sgml should be rewritten), need to teach pg_dump
about it, need to update contrib modules that currently build pg_opclass
entries by hand. Original patch by Bill Studenmund, grammar adjustments
and general update for 7.3 by Tom Lane.
Tom Lane