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[PATCH v3] popcount 2+ messages / 2 participants [nested] [flat]
* [PATCH v3] popcount @ 2020-12-30 10:51 David Fetter <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: David Fetter @ 2020-12-30 10:51 UTC (permalink / raw) Now it's accessible to SQL for the BIT VARYING and BYTEA types. diff --git doc/src/sgml/func.sgml doc/src/sgml/func.sgml index 02a37658ad..1d86d610dd 100644 --- doc/src/sgml/func.sgml +++ doc/src/sgml/func.sgml @@ -4069,6 +4069,23 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three'); </para></entry> </row> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>popcount</primary> + </indexterm> + <function>popcount</function> ( <parameter>bytes</parameter> <type>bytea</type> ) + <returnvalue>bigint</returnvalue> + </para> + <para> + Counts the number of bits set in a binary string. + </para> + <para> + <literal>popcount('\xdeadbeef'::bytea)</literal> + <returnvalue>24</returnvalue> + </para></entry> + </row> + <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> @@ -4830,6 +4847,24 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three'); <returnvalue>101010001010101010</returnvalue> </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>popcount</primary> + </indexterm> + <function>popcount</function> ( <parameter>bits</parameter> <type>bit</type> ) + <returnvalue>bigint</returnvalue> + </para> + <para> + Counts the bits set in a bit string. + </para> + <para> + <literal>popcount(B'101010101010101010')</literal> + <returnvalue>9</returnvalue> + </para></entry> + </row> + </tbody> </tgroup> </table> diff --git src/include/catalog/pg_proc.dat src/include/catalog/pg_proc.dat index d7b55f57ea..2d53e0d46d 100644 --- src/include/catalog/pg_proc.dat +++ src/include/catalog/pg_proc.dat @@ -1446,6 +1446,9 @@ { oid => '752', descr => 'substitute portion of string', proname => 'overlay', prorettype => 'bytea', proargtypes => 'bytea bytea int4', prosrc => 'byteaoverlay_no_len' }, +{ oid => '8436', descr => 'count set bits', + proname => 'popcount', prorettype => 'int8', proargtypes => 'bytea', + prosrc => 'byteapopcount'}, { oid => '725', proname => 'dist_pl', prorettype => 'float8', proargtypes => 'point line', @@ -3865,6 +3868,9 @@ { oid => '3033', descr => 'set bit', proname => 'set_bit', prorettype => 'bit', proargtypes => 'bit int4 int4', prosrc => 'bitsetbit' }, +{ oid => '8435', descr => 'count set bits', + proname => 'popcount', prorettype => 'int8', proargtypes => 'bit', + prosrc => 'bitpopcount'}, # for macaddr type support { oid => '436', descr => 'I/O', diff --git src/backend/utils/adt/varbit.c src/backend/utils/adt/varbit.c index 2235866244..a6a44f3f4f 100644 --- src/backend/utils/adt/varbit.c +++ src/backend/utils/adt/varbit.c @@ -36,6 +36,7 @@ #include "libpq/pqformat.h" #include "nodes/nodeFuncs.h" #include "nodes/supportnodes.h" +#include "port/pg_bitutils.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/varbit.h" @@ -1878,3 +1879,29 @@ bitgetbit(PG_FUNCTION_ARGS) else PG_RETURN_INT32(0); } + +/* + * bitpopcount + * + * Returns the number of bits set in a bit array. + * + */ +Datum +bitpopcount(PG_FUNCTION_ARGS) +{ + VarBit *arg1 = PG_GETARG_VARBIT_P(0); + bits8 *p; + int len; + int8 popcount; + + /* + * ceil(VARBITLEN(ARG1)/BITS_PER_BYTE) + * done to minimize branches and instructions. + */ + len = (VARBITLEN(arg1) + BITS_PER_BYTE + 1) / BITS_PER_BYTE; + p = VARBITS(arg1); + + popcount = pg_popcount((const char *)p, len); + + PG_RETURN_INT64(popcount); +} diff --git src/backend/utils/adt/varlena.c src/backend/utils/adt/varlena.c index 4838bfb4ff..da3ba769c4 100644 --- src/backend/utils/adt/varlena.c +++ src/backend/utils/adt/varlena.c @@ -3433,6 +3433,22 @@ bytea_overlay(bytea *t1, bytea *t2, int sp, int sl) return result; } +/* + * popcount + */ +Datum +byteapopcount(PG_FUNCTION_ARGS) +{ + bytea *t1 = PG_GETARG_BYTEA_PP(0); + int len; + int8 result; + + len = VARSIZE_ANY_EXHDR(t1); + result = pg_popcount(VARDATA_ANY(t1), len); + + PG_RETURN_INT64(result); +} + /* * byteapos - * Return the position of the specified substring. diff --git src/test/regress/expected/bit.out src/test/regress/expected/bit.out index a7f95b846d..228f992ced 100644 --- src/test/regress/expected/bit.out +++ src/test/regress/expected/bit.out @@ -710,6 +710,19 @@ SELECT overlay(B'0101011100' placing '001' from 20); 0101011100001 (1 row) +-- Popcount +SELECT popcount(B'0101011100'::bit(10)); + popcount +---------- + 5 +(1 row) + +SELECT popcount(B'1111111111'::bit(10)); + popcount +---------- + 10 +(1 row) + -- This table is intentionally left around to exercise pg_dump/pg_upgrade CREATE TABLE bit_defaults( b1 bit(4) DEFAULT '1001', diff --git src/test/regress/expected/strings.out src/test/regress/expected/strings.out index 595bd2446e..dd962e5f48 100644 --- src/test/regress/expected/strings.out +++ src/test/regress/expected/strings.out @@ -2167,3 +2167,10 @@ SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 5 Th\000o\x02\x03 (1 row) +SET bytea_output TO hex; +SELECT popcount(E'\\xdeadbeef'::bytea); + popcount +---------- + 24 +(1 row) + diff --git src/test/regress/sql/bit.sql src/test/regress/sql/bit.sql index ea01742c4a..fa77bf45c4 100644 --- src/test/regress/sql/bit.sql +++ src/test/regress/sql/bit.sql @@ -215,6 +215,10 @@ SELECT overlay(B'0101011100' placing '101' from 6); SELECT overlay(B'0101011100' placing '001' from 11); SELECT overlay(B'0101011100' placing '001' from 20); +-- Popcount +SELECT popcount(B'0101011100'::bit(10)); +SELECT popcount(B'1111111111'::bit(10)); + -- This table is intentionally left around to exercise pg_dump/pg_upgrade CREATE TABLE bit_defaults( b1 bit(4) DEFAULT '1001', diff --git src/test/regress/sql/strings.sql src/test/regress/sql/strings.sql index ca465d050f..48964e71cb 100644 --- src/test/regress/sql/strings.sql +++ src/test/regress/sql/strings.sql @@ -728,3 +728,6 @@ SELECT btrim(E'\\000trim\\000'::bytea, ''::bytea); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'Th\\001omas'::bytea from 2),'escape'); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 8),'escape'); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 5 for 3),'escape'); + +SET bytea_output TO hex; +SELECT popcount(E'\\xdeadbeef'::bytea); ^ permalink raw reply [nested|flat] 2+ messages in thread
* [PATCH v3 5/7] Row pattern recognition patch (docs). @ 2023-07-26 10:49 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++-- 3 files changed, 133 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index dcc9d6f59d..b333d62410 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..16478a3950 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Wed_Jul_26_21_21_34_2023_317)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v3-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2023-07-26 10:49 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-12-30 10:51 [PATCH v3] popcount David Fetter <[email protected]> 2023-07-26 10:49 [PATCH v3 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
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