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Revert temporal primary keys and foreign keys

Browse Source 
This feature set did not handle empty ranges correctly, and it's now
too late for PostgreSQL 17 to fix it.

The following commits are reverted:

    6db4598fcb Add stratnum GiST support function
    46a0cd4cef Add temporal PRIMARY KEY and UNIQUE constraints
    86232a49a4 Fix comment on gist_stratnum_btree
    030e10ff1a Rename pg_constraint.conwithoutoverlaps to conperiod
    a88c800deb Use daterange and YMD in without_overlaps tests instead of tsrange.
    5577a71fb0 Use half-open interval notation in without_overlaps tests
    34768ee361 Add temporal FOREIGN KEY contraints
    482e108cd3 Add test for REPLICA IDENTITY with a temporal key
    c3db1f30cb doc:  clarify PERIOD and WITHOUT OVERLAPS in CREATE TABLE
    144c2ce0cc Fix ON CONFLICT DO NOTHING/UPDATE for temporal indexes

Discussion: https://www.postgresql.org/message-id/d0b64a7a-dfe4-4b84-a906-c7dedfa40a3e@eisentraut.org
This commit is contained in:
Peter Eisentraut
2024-05-16 08:15:35 +02:00
parent f6ebb41831
commit 8aee330af5
47 changed files with 149 additions and 4475 deletions
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11
doc/src/sgml/catalogs.sgml
View File

@ -2729,17 +2729,6 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>conperiod</structfield> <type>bool</type>
</para>
<para>
This constraint is defined with <literal>WITHOUT OVERLAPS</literal>
(for primary keys and unique constraints) or <literal>PERIOD</literal>
(for foreign keys).
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>conkey</structfield> <type>int2[]</type>

77
doc/src/sgml/gist.sgml
View File

@ -266,7 +266,7 @@ CREATE INDEX ON my_table USING GIST (my_inet_column inet_ops);
<para>
There are five methods that an index operator class for
<acronym>GiST</acronym> must provide, and seven that are optional.
<acronym>GiST</acronym> must provide, and six that are optional.
Correctness of the index is ensured
by proper implementation of the <function>same</function>, <function>consistent</function>
and <function>union</function> methods, while efficiency (size and speed) of the
@ -289,11 +289,6 @@ CREATE INDEX ON my_table USING GIST (my_inet_column inet_ops);
user-specified parameters.
The optional eleventh method <function>sortsupport</function> is used to
speed up building a <acronym>GiST</acronym> index.
The optional twelfth method <function>stratnum</function> is used to
translate well-known <literal>RT*StrategyNumber</literal>s (from
<filename>src/include/access/stratnum.h</filename>) into strategy numbers
used by the operator class. This lets the core code look up operators for
temporal constraint indexes.
</para>
<variablelist>
@ -1168,76 +1163,6 @@ my_sortsupport(PG_FUNCTION_ARGS)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><function>stratnum</function></term>
<listitem>
<para>
Given an <literal>RT*StrategyNumber</literal> value from
<filename>src/include/access/stratnum.h</filename>, returns a strategy
number used by this operator class for matching functionality. The
function should return <literal>InvalidStrategy</literal> if the
operator class has no matching strategy.
</para>
<para>
This is used for temporal index constraints (i.e., <literal>PRIMARY
KEY</literal> and <literal>UNIQUE</literal>). If the operator class
provides this function and it returns results for
<literal>RTEqualStrategyNumber</literal>, it can be used in the
non-<literal>WITHOUT OVERLAPS</literal> part(s) of an index constraint.
If it returns results for <literal>RTOverlapStrategyNumber</literal>,
the operator class can be used in the <literal>WITHOUT
OVERLAPS</literal> part of an index constraint.
</para>
<para>
The <acronym>SQL</acronym> declaration of the function must look like
this:
<programlisting>
CREATE OR REPLACE FUNCTION my_stratnum(integer)
RETURNS integer
AS 'MODULE_PATHNAME'
LANGUAGE C STRICT;
</programlisting>
</para>
<para>
The matching code in the C module could then follow this skeleton:
<programlisting>
PG_FUNCTION_INFO_V1(my_stratnum);
Datum
my_stratnum(PG_FUNCTION_ARGS)
{
StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(1);
StrategyNumber ret = InvalidStrategy;
switch (strategy)
{
case RTEqualStrategyNumber:
ret = BTEqualStrategyNumber;
}
PG_RETURN_UINT16(ret);
}
</programlisting>
</para>
<para>
One translation function is provided by
<productname>PostgreSQL</productname>:
<literal>gist_stratnum_identity</literal> is for operator classes that
already use the <literal>RT*StrategyNumber</literal> constants. It
returns whatever is passed to it. The <literal>btree_gist</literal>
extension defines a second translation function,
<literal>gist_stratnum_btree</literal>, for operator classes that use
the <literal>BT*StrategyNumber</literal> constants.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>

94
doc/src/sgml/ref/create_table.sgml
View File

@ -77,10 +77,10 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
[ CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ]
{ CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] |
UNIQUE [ NULLS [ NOT ] DISTINCT ] ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] ) <replaceable class="parameter">index_parameters</replaceable> |
PRIMARY KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] ) <replaceable class="parameter">index_parameters</replaceable> |
UNIQUE [ NULLS [ NOT ] DISTINCT ] ( <replaceable class="parameter">column_name</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> |
PRIMARY KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> |
EXCLUDE [ USING <replaceable class="parameter">index_method</replaceable> ] ( <replaceable class="parameter">exclude_element</replaceable> WITH <replaceable class="parameter">operator</replaceable> [, ... ] ) <replaceable class="parameter">index_parameters</replaceable> [ WHERE ( <replaceable class="parameter">predicate</replaceable> ) ] |
FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, PERIOD <replaceable class="parameter">column_name</replaceable> ] ) REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ] [, PERIOD <replaceable class="parameter">column_name</replaceable> ] ) ]
FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] ) REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ] ) ]
[ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE <replaceable
class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ] }
[ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
@ -964,7 +964,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<varlistentry id="sql-createtable-parms-unique">
<term><literal>UNIQUE [ NULLS [ NOT ] DISTINCT ]</literal> (column constraint)</term>
<term><literal>UNIQUE [ NULLS [ NOT ] DISTINCT ] ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] )</literal>
<term><literal>UNIQUE [ NULLS [ NOT ] DISTINCT ] ( <replaceable class="parameter">column_name</replaceable> [, ... ] )</literal>
<optional> <literal>INCLUDE ( <replaceable class="parameter">column_name</replaceable> [, ...])</literal> </optional> (table constraint)</term>
<listitem>
@ -978,30 +978,6 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
of these columns.
</para>
<para>
If the <literal>WITHOUT OVERLAPS</literal> option is specified for the
last column, then that column is checked for overlaps instead of
equality. In that case, the other columns of the constraint will allow
duplicates so long as the duplicates don't overlap in the
<literal>WITHOUT OVERLAPS</literal> column. (This is sometimes called a
temporal key, if the column is a range of dates or timestamps, but
PostgreSQL allows ranges over any base type.) In effect, such a
constraint is enforced with an <literal>EXCLUDE</literal> constraint
rather than a <literal>UNIQUE</literal> constraint. So for example
<literal>UNIQUE (id, valid_at WITHOUT OVERLAPS)</literal> behaves like
<literal>EXCLUDE USING GIST (id WITH =, valid_at WITH
&amp;&amp;)</literal>. The <literal>WITHOUT OVERLAPS</literal> column
must have a range or multirange type. (Technically, any type is allowed
whose default GiST opclass includes an overlaps operator. See the
<literal>stratnum</literal> support function under <xref
linkend="gist-extensibility"/> for details.) The non-<literal>WITHOUT
OVERLAPS</literal> columns of the constraint can be any type that can be
compared for equality in a GiST index. By default, only range types are
supported, but you can use other types by adding the <xref
linkend="btree-gist"/> extension (which is the expected way to use this
feature).
</para>
<para>
For the purpose of a unique constraint, null values are not
considered equal, unless <literal>NULLS NOT DISTINCT</literal> is
@ -1023,11 +999,9 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
</para>
<para>
Adding a unique constraint will automatically create a unique B-tree
index on the column or group of columns used in the constraint. But if
the constraint includes a <literal>WITHOUT OVERLAPS</literal> clause, it
will use a GiST index. The created index has the same name as the unique
constraint.
Adding a unique constraint will automatically create a unique btree
index on the column or group of columns used in the constraint. The
created index has the same name as the unique constraint.
</para>
<para>
@ -1045,7 +1019,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<varlistentry id="sql-createtable-parms-primary-key">
<term><literal>PRIMARY KEY</literal> (column constraint)</term>
<term><literal>PRIMARY KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, <replaceable class="parameter">column_name</replaceable> WITHOUT OVERLAPS ] )</literal>
<term><literal>PRIMARY KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] )</literal>
<optional> <literal>INCLUDE ( <replaceable class="parameter">column_name</replaceable> [, ...])</literal> </optional> (table constraint)</term>
<listitem>
<para>
@ -1078,11 +1052,10 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
</para>
<para>
As with a <literal>UNIQUE</literal> constraint, adding a
<literal>PRIMARY KEY</literal> constraint will automatically create a
unique B-tree index, or GiST if <literal>WITHOUT OVERLAPS</literal> was
specified, on the column or group of columns used in the constraint.
That index has the same name as the primary key constraint.
Adding a <literal>PRIMARY KEY</literal> constraint will automatically
create a unique btree index on the column or group of columns used in
the constraint. That index has the same name as the primary key
constraint.
</para>
<para>
@ -1151,8 +1124,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<varlistentry id="sql-createtable-parms-references">
<term><literal>REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> ) ] [ MATCH <replaceable class="parameter">matchtype</replaceable> ] [ ON DELETE <replaceable class="parameter">referential_action</replaceable> ] [ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ]</literal> (column constraint)</term>
<term><literal>FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] [, PERIOD <replaceable class="parameter">column_name</replaceable> ] )
REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ] [, PERIOD <replaceable class="parameter">column_name</replaceable> ] ) ]
<term><literal>FOREIGN KEY ( <replaceable class="parameter">column_name</replaceable> [, ... ] )
REFERENCES <replaceable class="parameter">reftable</replaceable> [ ( <replaceable class="parameter">refcolumn</replaceable> [, ... ] ) ]
[ MATCH <replaceable class="parameter">matchtype</replaceable> ]
[ ON DELETE <replaceable class="parameter">referential_action</replaceable> ]
[ ON UPDATE <replaceable class="parameter">referential_action</replaceable> ]</literal>
@ -1168,32 +1141,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
primary key of the <replaceable class="parameter">reftable</replaceable>
is used. Otherwise, the <replaceable class="parameter">refcolumn</replaceable>
list must refer to the columns of a non-deferrable unique or primary key
constraint or be the columns of a non-partial unique index.
</para>
<para>
If the last column is marked with <literal>PERIOD</literal>, it is
treated in a special way. While the non-<literal>PERIOD</literal>
columns are compared for equality (and there must be at least one of
them), the <literal>PERIOD</literal> column is not. Instead, the
constraint is considered satisfied if the referenced table has matching
records (based on the non-<literal>PERIOD</literal> parts of the key)
whose combined <literal>PERIOD</literal> values completely cover the
referencing record's. In other words, the reference must have a
referent for its entire duration. This column must be a range or
multirange type. In addition, the referenced table must have a primary
key or unique constraint declared with <literal>WITHOUT
OVERLAPS</literal>. Finally, if the foreign key has a PERIOD
<replaceable class="parameter">column_name</replaceable> specification
the corresponding <replaceable class="parameter">refcolumn</replaceable>,
if present, must also be marked <literal>PERIOD</literal>. If the
<replaceable class="parameter">refcolumn</replaceable> clause is omitted,
and thus the reftable's primary key constraint chosen, the primary key
must have its final column marked <literal>WITHOUT OVERLAPS</literal>.
</para>
<para>
The user
constraint or be the columns of a non-partial unique index. The user
must have <literal>REFERENCES</literal> permission on the referenced
table (either the whole table, or the specific referenced columns). The
addition of a foreign key constraint requires a
@ -1267,10 +1215,6 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
values of the referencing column(s) to the new values of the
referenced columns, respectively.
</para>
<para>
In a temporal foreign key, this option is not supported.
</para>
</listitem>
</varlistentry>
@ -1282,10 +1226,6 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
referencing columns, to null. A subset of columns can only be
specified for <literal>ON DELETE</literal> actions.
</para>
<para>
In a temporal foreign key, this option is not supported.
</para>
</listitem>
</varlistentry>
@ -1299,10 +1239,6 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
(There must be a row in the referenced table matching the default
values, if they are not null, or the operation will fail.)
</para>
<para>
In a temporal foreign key, this option is not supported.
</para>
</listitem>
</varlistentry>
</variablelist>

8
doc/src/sgml/xindex.sgml
View File

@ -508,7 +508,7 @@
</table>
<para>
GiST indexes have twelve support functions, seven of which are optional,
GiST indexes have eleven support functions, six of which are optional,
as shown in <xref linkend="xindex-gist-support-table"/>.
(For more information see <xref linkend="gist"/>.)
</para>
@ -590,12 +590,6 @@
(optional)</entry>
<entry>11</entry>
</row>
<row>
<entry><function>stratnum</function></entry>
<entry>translate well-known strategy numbers to ones
used by the operator class (optional)</entry>
<entry>12</entry>
</row>
</tbody>
</tgroup>
</table>