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Postgres FD Implementation
Commit b6d15590 authored by Tom Lane's avatar Tom Lane
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Add timestamp and timestamptz versions of generate_series(). 

Hitoshi Harada
parent 600da67f
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Showing with 229 additions and 15 deletions
doc/src/sgml/func.sgml
View file @ b6d15590
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.435 2008/05/04 21:13:35 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.436 2008/05/04 23:19:23 tgl Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
......@@ -10650,6 +10650,16 @@ AND
</entry>
</row>
<row>
<entry><literal><function>generate_series</function>(<parameter>start</parameter>, <parameter>stop</parameter>, <parameter>step</parameter> <type>interval</>)</literal></entry>
<entry><type>timestamp</type> or <type>timestamp with time zone</type></entry>
<entry><type>setof timestamp</type> or <type>setof timestamp with time zone</type> (same as argument type)</entry>
<entry>
Generate a series of values, from <parameter>start</parameter> to <parameter>stop</parameter>
with a step size of <parameter>step</parameter>
</entry>
</row>
</tbody>
</tgroup>
</table>
......@@ -10683,6 +10693,7 @@ select * from generate_series(4,3);
-----------------
(0 rows)
-- this example relies on the date-plus-integer operator
select current_date + s.a as dates from generate_series(0,14,7) as s(a);
dates
------------
......@@ -10690,16 +10701,26 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a);
2004-02-12
2004-02-19
(3 rows)
select * from generate_series('2008-03-01 00:00'::timestamp,
'2008-03-04 12:00', '10 hours');
generate_series
---------------------
2008-03-01 00:00:00
2008-03-01 10:00:00
2008-03-01 20:00:00
2008-03-02 06:00:00
2008-03-02 16:00:00
2008-03-03 02:00:00
2008-03-03 12:00:00
2008-03-03 22:00:00
2008-03-04 08:00:00
(9 rows)
</programlisting>
</para>
<table id="functions-srf-subscripts">
<indexterm>
<primary>generate_subscripts</primary>
</indexterm>
<title>Subscripts Generating Functions</title>
<title>Subscript Generating Functions</title>
<tgroup cols="3">
<thead>
<row>
......@@ -10711,7 +10732,7 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a);
<tbody>
<row>
<entry><literal><function>generate_subscripts</function>(<parameter>array annyarray</parameter>, <parameter>dim int</parameter>)</literal></entry>
<entry><literal><function>generate_subscripts</function>(<parameter>array anyarray</parameter>, <parameter>dim int</parameter>)</literal></entry>
<entry><type>setof int</type></entry>
<entry>
Generate a series comprising the given array's subscripts.
......@@ -10719,7 +10740,7 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a);
</row>
<row>
<entry><literal><function>generate_subscripts</function>(<parameter>array annyarray</parameter>, <parameter>dim int</parameter>, <parameter>reverse boolean</parameter>)</literal></entry>
<entry><literal><function>generate_subscripts</function>(<parameter>array anyarray</parameter>, <parameter>dim int</parameter>, <parameter>reverse boolean</parameter>)</literal></entry>
<entry><type>setof int</type></entry>
<entry>
Generate a series comprising the given array's subscripts. When
......@@ -10732,10 +10753,17 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a);
</tgroup>
</table>
<indexterm>
<primary>generate_subscripts</primary>
</indexterm>
<para>
<function>generate_subscripts</> is a convenience function that generates
the set of valid subscripts for the specified dimension of the given
array.
Zero rows are returned for arrays that do not have the requested dimension,
or for NULL arrays (but valid subscripts are returned for NULL array
elements.) Some examples follow:
elements). Some examples follow:
<programlisting>
-- basic usage
select generate_subscripts('{NULL,1,NULL,2}'::int[], 1) as s;
......
src/backend/utils/adt/timestamp.c
View file @ b6d15590
......@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.188 2008/05/04 21:13:35 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.189 2008/05/04 23:19:23 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -24,6 +24,7 @@
#include "access/hash.h"
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "parser/scansup.h"
......@@ -45,6 +46,22 @@ TimestampTz PgStartTime;
/* Set at configuration reload */
TimestampTz PgReloadTime;
typedef struct
{
Timestamp current;
Timestamp finish;
Interval step;
int step_sign;
} generate_series_timestamp_fctx;
typedef struct
{
TimestampTz current;
TimestampTz finish;
Interval step;
int step_sign;
} generate_series_timestamptz_fctx;
static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
static int EncodeSpecialTimestamp(Timestamp dt, char *str);
......@@ -4651,3 +4668,165 @@ timestamptz_izone(PG_FUNCTION_ARGS)
PG_RETURN_TIMESTAMP(result);
}
/* generate_series_timestamp()
* Generate the set of timestamps from start to finish by step
*/
Datum
generate_series_timestamp(PG_FUNCTION_ARGS)
{
FuncCallContext *funcctx;
generate_series_timestamp_fctx *fctx;
Timestamp result;
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
Timestamp start = PG_GETARG_TIMESTAMP(0);
Timestamp finish = PG_GETARG_TIMESTAMP(1);
Interval *step = PG_GETARG_INTERVAL_P(2);
MemoryContext oldcontext;
Interval interval_zero;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (generate_series_timestamp_fctx *)
palloc(sizeof(generate_series_timestamp_fctx));
/*
* Use fctx to keep state from call to call. Seed current with the
* original start value
*/
fctx->current = start;
fctx->finish = finish;
fctx->step = *step;
/* Determine sign of the interval */
MemSet(&interval_zero, 0, sizeof(Interval));
fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
if (fctx->step_sign == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("step size cannot equal zero")));
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
/* stuff done on every call of the function */
funcctx = SRF_PERCALL_SETUP();
/*
* get the saved state and use current as the result for this iteration
*/
fctx = funcctx->user_fctx;
result = fctx->current;
if (fctx->step_sign > 0 ?
timestamp_cmp_internal(result, fctx->finish) <= 0 :
timestamp_cmp_internal(result, fctx->finish) >= 0)
{
/* increment current in preparation for next iteration */
fctx->current = DatumGetTimestamp(
DirectFunctionCall2(timestamp_pl_interval,
TimestampGetDatum(fctx->current),
PointerGetDatum(&fctx->step)));
/* do when there is more left to send */
SRF_RETURN_NEXT(funcctx, TimestampGetDatum(result));
}
else
{
/* do when there is no more left */
SRF_RETURN_DONE(funcctx);
}
}
/* generate_series_timestamptz()
* Generate the set of timestamps from start to finish by step
*/
Datum
generate_series_timestamptz(PG_FUNCTION_ARGS)
{
FuncCallContext *funcctx;
generate_series_timestamptz_fctx *fctx;
TimestampTz result;
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
TimestampTz start = PG_GETARG_TIMESTAMPTZ(0);
TimestampTz finish = PG_GETARG_TIMESTAMPTZ(1);
Interval *step = PG_GETARG_INTERVAL_P(2);
MemoryContext oldcontext;
Interval interval_zero;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (generate_series_timestamptz_fctx *)
palloc(sizeof(generate_series_timestamptz_fctx));
/*
* Use fctx to keep state from call to call. Seed current with the
* original start value
*/
fctx->current = start;
fctx->finish = finish;
fctx->step = *step;
/* Determine sign of the interval */
MemSet(&interval_zero, 0, sizeof(Interval));
fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
if (fctx->step_sign == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("step size cannot equal zero")));
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
/* stuff done on every call of the function */
funcctx = SRF_PERCALL_SETUP();
/*
* get the saved state and use current as the result for this iteration
*/
fctx = funcctx->user_fctx;
result = fctx->current;
if (fctx->step_sign > 0 ?
timestamp_cmp_internal(result, fctx->finish) <= 0 :
timestamp_cmp_internal(result, fctx->finish) >= 0)
{
/* increment current in preparation for next iteration */
fctx->current = DatumGetTimestampTz(
DirectFunctionCall2(timestamptz_pl_interval,
TimestampTzGetDatum(fctx->current),
PointerGetDatum(&fctx->step)));
/* do when there is more left to send */
SRF_RETURN_NEXT(funcctx, TimestampTzGetDatum(result));
}
else
{
/* do when there is no more left */
SRF_RETURN_DONE(funcctx);
}
}
src/include/catalog/catversion.h
View file @ b6d15590
......@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.454 2008/05/04 21:13:35 tgl Exp $
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.455 2008/05/04 23:19:23 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 200805041
#define CATALOG_VERSION_NO 200805042
#endif
src/include/catalog/pg_proc.h
View file @ b6d15590
......@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.495 2008/05/04 21:13:36 tgl Exp $
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.496 2008/05/04 23:19:23 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
......@@ -3872,6 +3872,10 @@ DATA(insert OID = 1068 ( generate_series PGNSP PGUID 12 1 1000 f f t t i 3 20 "
DESCR("non-persistent series generator");
DATA(insert OID = 1069 ( generate_series PGNSP PGUID 12 1 1000 f f t t i 2 20 "20 20" _null_ _null_ _null_ generate_series_int8 - _null_ _null_ ));
DESCR("non-persistent series generator");
DATA(insert OID = 938 ( generate_series PGNSP PGUID 12 1 1000 f f t t i 3 1114 "1114 1114 1186" _null_ _null_ _null_ generate_series_timestamp - _null_ _null_ ));
DESCR("non-persistent series generator");
DATA(insert OID = 939 ( generate_series PGNSP PGUID 12 1 1000 f f t t s 3 1184 "1184 1184 1186" _null_ _null_ _null_ generate_series_timestamptz - _null_ _null_ ));
DESCR("non-persistent series generator");
/* boolean aggregates */
DATA(insert OID = 2515 ( booland_statefunc PGNSP PGUID 12 1 0 f f t f i 2 16 "16 16" _null_ _null_ _null_ booland_statefunc - _null_ _null_ ));
......
src/include/utils/timestamp.h
View file @ b6d15590
......@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.77 2008/05/04 21:13:36 tgl Exp $
* $PostgreSQL: pgsql/src/include/utils/timestamp.h,v 1.78 2008/05/04 23:19:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -308,6 +308,9 @@ extern Datum clock_timestamp(PG_FUNCTION_ARGS);
extern Datum pg_postmaster_start_time(PG_FUNCTION_ARGS);
extern Datum pg_conf_load_time(PG_FUNCTION_ARGS);
extern Datum generate_series_timestamp(PG_FUNCTION_ARGS);
extern Datum generate_series_timestamptz(PG_FUNCTION_ARGS);
/* Internal routines (not fmgr-callable) */
extern TimestampTz GetCurrentTimestamp(void);
......
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