Since PG 8.2, @ and ~ have been deprecated aliases for the containment
operators @> and <@. It seems like enough time has passed to actually
remove them, so do so.
This completes the project begun in commit 2f70fdb06. Note that in
the core types, the relation to the preferred operator names was
reversed from what it is in these contrib modules. The confusion
that induced was a large part of the reason for deprecation.
Justin Pryzby
Discussion: https://postgr.es/m/20201027032511.GF9241@telsasoft.com
Since commit efc77cf5f, an indexed query using <@ has required a
full-index scan, so that it actually performs worse than a plain seqscan
would do. As I noted at the time, we'd be better off to not treat <@ as
being indexable by such indexes at all; and that's what this patch does.
It would have been difficult to remove these opclass members without
dropping the whole opclass before commit 9f9682783 fixed GiST opclass
member dependency rules, but now it's quite simple, so let's do it.
I left the existing support code in place for the time being, with
comments noting it's now unreachable. At some point, perhaps we should
remove that code in favor of throwing an error telling people to upgrade
the extension version.
Discussion: https://postgr.es/m/2176979.1596389859@sss.pgh.pa.us
Discussion: https://postgr.es/m/458.1565114141@sss.pgh.pa.us
This converts the contrib documentation to the new style, and mops up
a couple of function tables that were outside chapter 9 in the main
docs.
A few contrib modules choose not to present their functions in the
standard tabular format. There might be room to rethink those decisions
now that the standard format is more friendly to verbose descriptions.
But I have not undertaken to do that here; I just converted existing
tables.
PostgreSQL provides set of template index access methods, where opclasses have
much freedom in the semantics of indexing. These index AMs are GiST, GIN,
SP-GiST and BRIN. There opclasses define representation of keys, operations on
them and supported search strategies. So, it's natural that opclasses may be
faced some tradeoffs, which require user-side decision. This commit implements
opclass parameters allowing users to set some values, which tell opclass how to
index the particular dataset.
This commit doesn't introduce new storage in system catalog. Instead it uses
pg_attribute.attoptions, which is used for table column storage options but
unused for index attributes.
In order to evade changing signature of each opclass support function, we
implement unified way to pass options to opclass support functions. Options
are set to fn_expr as the constant bytea expression. It's possible due to the
fact that opclass support functions are executed outside of expressions, so
fn_expr is unused for them.
This commit comes with some examples of opclass options usage. We parametrize
signature length in GiST. That applies to multiple opclasses: tsvector_ops,
gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and
gist_hstore_ops. Also we parametrize maximum number of integer ranges for
gist__int_ops. However, the main future usage of this feature is expected
to be json, where users would be able to specify which way to index particular
json parts.
Catversion is bumped.
Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru
Author: Nikita Glukhov, revised by me
Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
This allows these modules to be installed into a database without
superuser privileges (assuming that the DBA or sysadmin has installed
the module's files in the expected place). You only need CREATE
privilege on the current database, which by default would be
available to the database owner.
The following modules are marked trusted:
btree_gin
btree_gist
citext
cube
dict_int
earthdistance
fuzzystrmatch
hstore
hstore_plperl
intarray
isn
jsonb_plperl
lo
ltree
pg_trgm
pgcrypto
seg
tablefunc
tcn
tsm_system_rows
tsm_system_time
unaccent
uuid-ossp
In the future we might mark some more modules trusted, but there
seems to be no debate about these, and on the whole it seems wise
to be conservative with use of this feature to start out with.
Discussion: https://postgr.es/m/32315.1580326876@sss.pgh.pa.us
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
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
Correct obsolete install instructions, as noted by Daniel Gustafsson.
Clarify the test code's prerequisites.
Discussion: <88E617F2-7721-4C4E-84F4-886A2041C1D0@yesql.se>
The array containment operators now behave per mathematical expectation
for empty arrays (ie, an empty array is contained in anything).
Both these operators and the query_int operators now work as expected in
GiST and GIN index searches, rather than having corner cases where the
index searches gave different answers.
Also, fix unexpected failures where the operators would claim that an array
contained nulls, when in fact there was no longer any null present (similar
to bug #5784). The restriction to not have nulls is still there, as
removing it would take a lot of added code complexity and probably slow
things down significantly.
Also, remove the arbitrary restriction to 1-D arrays; unlike the other
restriction, this was buying us nothing performance-wise.
Assorted cosmetic improvements and marginal performance improvements, too.
Block elements with verbatim formatting (literallayout, programlisting,
screen, synopsis) should be aligned at column 0 independent of the surrounding
SGML, because whitespace is significant, and indenting them creates erratic
whitespace in the output. The CSS stylesheets already take care of indenting
the output.
Assorted markup improvements to go along with it.
the <@ and @> operators. These are not in fact equivalent to the built-in
anyarray operators of the same names, because they have different behavior for
empty arrays, namely they don't think empty arrays are contained in anything.
That is mathematically wrong, no doubt, but until we can persuade GIN indexes
to implement the mathematical definition we should probably not change this.
Another reason for not changing it now is that we can't yet ensure the
opclasses will be updated correctly in a dump-and-reload upgrade. Per
recent discussions.
don't cause confusion with the built-in anyarray versions of those operators.
Adjust the module's index opclasses to support the built-in operators in place
of the private ones.
The private implementations are still available under their historical
names @ and ~, so no functionality is lost. Some quick testing suggests
that they offer no real benefit over the core operators, however.
Per a complaint from Rusty Conover.
Tom Lane
Alexander Korotkov
Peter Eisentraut
Bruce Momjian
Magnus Hagander
Heikki Linnakangas