-<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.4 2004/05/14 18:04:02 neilc Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.5 2004/05/14 21:42:27 neilc Exp $ -->
<appendix id="errcodes-appendix">
<title><productname>PostgreSQL</productname> Error Codes</title>
<entry>INTERVAL FIELD OVERFLOW</entry>
</row>
+<row>
+<entry><literal>2201G</literal></entry>
+<entry>INVALID ARGUMENT FOR WIDTH BUCKET FUNCTION</entry>
+</row>
+
<row>
<entry><literal>22018</literal></entry>
<entry>INVALID CHARACTER VALUE FOR CAST</entry>
<!--
-$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.201 2004/05/10 22:44:42 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.202 2004/05/14 21:42:27 neilc Exp $
PostgreSQL documentation
-->
<entry><literal>42.43</literal></entry>
</row>
+ <row>
+ <entry><literal><function>width_bucket</function>(<parameter>op</parameter> <type>numeric</type>, <parameter>b1</parameter> <type>numeric</type>, <parameter>b2</parameter> <type>numeric</type>, <parameter>count</parameter> <type>integer</type>)</literal></entry>
+ <entry><type>integer</type></entry>
+ <entry>return the bucket to which <parameter>operand</> would
+ be assigned in an equidepth histogram with <parameter>count</>
+ buckets, an upper bound of <parameter>b1</>, and a lower bound
+ of <parameter>b2</></entry>
+ <entry><literal>width_bucket(5.35, 0.024, 10.06, 5)</literal></entry>
+ <entry><literal>3</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
<!--
-$PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.82 2004/05/10 22:44:43 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.83 2004/05/14 21:42:27 neilc Exp $
-->
<sect1 id="xfunc">
</para>
<para>
- It's easiest to define <acronym>SQL</acronym>
+ It's easiest to define <acronym>SQL</acronym>
functions, so we'll start by discussing those.
Most of the concepts presented for <acronym>SQL</acronym> functions
will carry over to the other types of functions.
<para>
Throughout this chapter, it can be useful to look at the reference
- page of the <command>CREATE FUNCTION</command> command to
- understand the examples better.
- Some examples from this chapter
- can be found in <filename>funcs.sql</filename>
- and <filename>funcs.c</filename> in the <filename>src/tutorial</>
- directory in the <productname>PostgreSQL</productname> source distribution.
+ page of the <xref linkend="sql-createfunction"> command to
+ understand the examples better. Some examples from this chapter
+ can be found in <filename>funcs.sql</filename> and
+ <filename>funcs.c</filename> in the <filename>src/tutorial</>
+ directory in the <productname>PostgreSQL</productname> source
+ distribution.
</para>
</sect1>
* Copyright (c) 1998-2003, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.73 2004/05/07 00:24:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.74 2004/05/14 21:42:28 neilc Exp $
*
*-------------------------------------------------------------------------
*/
static void apply_typmod(NumericVar *var, int32 typmod);
+static int32 numericvar_to_int4(NumericVar *var);
static bool numericvar_to_int8(NumericVar *var, int64 *result);
static void int8_to_numericvar(int64 val, NumericVar *var);
static double numeric_to_double_no_overflow(Numeric num);
static void round_var(NumericVar *var, int rscale);
static void trunc_var(NumericVar *var, int rscale);
static void strip_var(NumericVar *var);
+static void compute_bucket(Numeric operand, Numeric bound1, Numeric bound2,
+ NumericVar *count_var, NumericVar *result_var);
/* ----------------------------------------------------------------------
PG_RETURN_NUMERIC(res);
}
+/*
+ * width_bucket_numeric() -
+ *
+ * 'bound1' and 'bound2' are the lower and upper bounds of the
+ * histogram's range, respectively. 'count' is the number of buckets
+ * in the histogram. width_bucket() returns an integer indicating the
+ * bucket number that 'operand' belongs in for an equiwidth histogram
+ * with the specified characteristics. An operand smaller than the
+ * lower bound is assigned to bucket 0. An operand greater than the
+ * upper bound is assigned to an additional bucket (with number
+ * count+1).
+ */
+Datum
+width_bucket_numeric(PG_FUNCTION_ARGS)
+{
+ Numeric operand = PG_GETARG_NUMERIC(0);
+ Numeric bound1 = PG_GETARG_NUMERIC(1);
+ Numeric bound2 = PG_GETARG_NUMERIC(2);
+ int32 count = PG_GETARG_INT32(3);
+ NumericVar count_var;
+ NumericVar result_var;
+ int32 result;
+
+ if (count <= 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("count must be greater than zero")));
+
+ init_var(&result_var);
+ init_var(&count_var);
+
+ /* Convert 'count' to a numeric, for ease of use later */
+ int8_to_numericvar((int64) count, &count_var);
+
+ switch (cmp_numerics(bound1, bound2))
+ {
+ case 0:
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("lower bound cannot equal upper bound")));
+
+ /* bound1 < bound2 */
+ case -1:
+ if (cmp_numerics(operand, bound1) < 0)
+ set_var_from_var(&const_zero, &result_var);
+ else if (cmp_numerics(operand, bound2) >= 0)
+ add_var(&count_var, &const_one, &result_var);
+ else
+ compute_bucket(operand, bound1, bound2,
+ &count_var, &result_var);
+ break;
+
+ /* bound1 > bound2 */
+ case 1:
+ if (cmp_numerics(operand, bound1) > 0)
+ set_var_from_var(&const_zero, &result_var);
+ else if (cmp_numerics(operand, bound2) <= 0)
+ add_var(&count_var, &const_one, &result_var);
+ else
+ compute_bucket(operand, bound1, bound2,
+ &count_var, &result_var);
+ break;
+ }
+
+ result = numericvar_to_int4(&result_var);
+
+ free_var(&count_var);
+ free_var(&result_var);
+
+ PG_RETURN_INT32(result);
+}
+
+/*
+ * compute_bucket() -
+ *
+ * If 'operand' is not outside the bucket range, determine the correct
+ * bucket for it to go. The calculations performed by this function
+ * are derived directly from the SQL2003 spec.
+ */
+static void
+compute_bucket(Numeric operand, Numeric bound1, Numeric bound2,
+ NumericVar *count_var, NumericVar *result_var)
+{
+ NumericVar bound1_var;
+ NumericVar bound2_var;
+ NumericVar operand_var;
+
+ init_var(&bound1_var);
+ init_var(&bound2_var);
+ init_var(&operand_var);
+
+ set_var_from_num(bound1, &bound1_var);
+ set_var_from_num(bound2, &bound2_var);
+ set_var_from_num(operand, &operand_var);
+
+ if (cmp_var(&bound1_var, &bound2_var) < 0)
+ {
+ sub_var(&operand_var, &bound1_var, &operand_var);
+ sub_var(&bound2_var, &bound1_var, &bound2_var);
+ div_var(&operand_var, &bound2_var, result_var,
+ select_div_scale(&operand_var, &bound2_var));
+ }
+ else
+ {
+ sub_var(&bound1_var, &operand_var, &operand_var);
+ sub_var(&bound1_var, &bound2_var, &bound1_var);
+ div_var(&operand_var, &bound1_var, result_var,
+ select_div_scale(&operand_var, &bound1_var));
+ }
+
+ mul_var(result_var, count_var, result_var,
+ result_var->dscale + count_var->dscale);
+ add_var(result_var, &const_one, result_var);
+ floor_var(result_var, result_var);
+
+ free_var(&bound1_var);
+ free_var(&bound2_var);
+ free_var(&operand_var);
+}
/* ----------------------------------------------------------------------
*
{
Numeric num = PG_GETARG_NUMERIC(0);
NumericVar x;
- int64 val;
int32 result;
/* XXX would it be better to return NULL? */
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert NaN to integer")));
- /* Convert to variable format and thence to int8 */
+ /* Convert to variable format, then convert to int4 */
init_var(&x);
set_var_from_num(num, &x);
+ result = numericvar_to_int4(&x);
+ free_var(&x);
+ PG_RETURN_INT32(result);
+}
- if (!numericvar_to_int8(&x, &val))
+/*
+ * Given a NumericVar, convert it to an int32. If the NumericVar
+ * exceeds the range of an int32, raise the appropriate error via
+ * ereport(). The input NumericVar is *not* free'd.
+ */
+static int32
+numericvar_to_int4(NumericVar *var)
+{
+ int32 result;
+ int64 val;
+
+ if (!numericvar_to_int8(var, &val))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
- free_var(&x);
-
/* Down-convert to int4 */
result = (int32) val;
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
- PG_RETURN_INT32(result);
+ return result;
}
-
Datum
int8_numeric(PG_FUNCTION_ARGS)
{
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.229 2004/05/10 22:44:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.230 2004/05/14 21:42:28 neilc Exp $
*
*-------------------------------------------------------------------------
*/
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 200405101
+#define CATALOG_VERSION_NO 200405141
#endif
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.328 2004/05/07 16:57:16 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.329 2004/05/14 21:42:28 neilc Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
DESCR("(internal)");
DATA(insert OID = 1746 ( float8 PGNSP PGUID 12 f f t f i 1 701 "1700" _null_ numeric_float8 - _null_ ));
DESCR("(internal)");
+DATA(insert OID = 2170 ( width_bucket PGNSP PGUID 12 f f t f i 4 23 "1700 1700 1700 23" _null_ width_bucket_numeric - _null_ ));
+DESCR("bucket number of operand in equidepth histogram");
DATA(insert OID = 1747 ( time_pl_interval PGNSP PGUID 12 f f t f i 2 1083 "1083 1186" _null_ time_pl_interval - _null_ ));
DESCR("plus");
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.237 2004/05/05 04:48:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.238 2004/05/14 21:42:30 neilc Exp $
*
*-------------------------------------------------------------------------
*/
extern Datum int2_avg_accum(PG_FUNCTION_ARGS);
extern Datum int4_avg_accum(PG_FUNCTION_ARGS);
extern Datum int8_avg(PG_FUNCTION_ARGS);
+extern Datum width_bucket_numeric(PG_FUNCTION_ARGS);
/* ri_triggers.c */
extern Datum RI_FKey_check_ins(PG_FUNCTION_ARGS);
*
* Copyright (c) 2003, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.9 2004/05/14 18:04:02 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.10 2004/05/14 21:42:30 neilc Exp $
*
*-------------------------------------------------------------------------
*/
#define ERRCODE_ESCAPE_CHARACTER_CONFLICT MAKE_SQLSTATE('2','2', '0','0','B')
#define ERRCODE_INDICATOR_OVERFLOW MAKE_SQLSTATE('2','2', '0','2','2')
#define ERRCODE_INTERVAL_FIELD_OVERFLOW MAKE_SQLSTATE('2','2', '0','1','5')
+#define ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION MAKE_SQLSTATE('2','2', '0', '1', 'G')
#define ERRCODE_INVALID_CHARACTER_VALUE_FOR_CAST MAKE_SQLSTATE('2','2', '0','1','8')
#define ERRCODE_INVALID_DATETIME_FORMAT MAKE_SQLSTATE('2','2', '0','0','7')
#define ERRCODE_INVALID_ESCAPE_CHARACTER MAKE_SQLSTATE('2','2', '0','1','9')
(7 rows)
DROP TABLE ceil_floor_round;
+-- Testing for width_bucket()
+-- NULL result
+SELECT width_bucket(NULL, NULL, NULL, NULL);
+ width_bucket
+--------------
+
+(1 row)
+
+-- errors
+SELECT width_bucket(5.0, 3.0, 4.0, 0);
+ERROR: count must be greater than zero
+SELECT width_bucket(5.0, 3.0, 4.0, -5);
+ERROR: count must be greater than zero
+SELECT width_bucket(3.0, 3.0, 3.0, 888);
+ERROR: lower bound cannot equal upper bound
+-- normal operation
+CREATE TABLE width_bucket_test (operand numeric);
+COPY width_bucket_test FROM stdin;
+SELECT
+ operand,
+ width_bucket(operand, 0, 10, 5) AS wb_1,
+ width_bucket(operand, 10, 0, 5) AS wb_2,
+ width_bucket(operand, 2, 8, 4) AS wb_3,
+ width_bucket(operand, 5.0, 5.5, 20) AS wb_4,
+ width_bucket(operand, -25, 25, 10) AS wb_5
+ FROM width_bucket_test;
+ operand | wb_1 | wb_2 | wb_3 | wb_4 | wb_5
+------------------+------+------+------+------+------
+ -5.2 | 0 | 6 | 0 | 0 | 4
+ -0.0000000000001 | 0 | 6 | 0 | 0 | 5
+ 0.0000000000001 | 1 | 5 | 0 | 0 | 6
+ 1 | 1 | 5 | 0 | 0 | 6
+ 1.99999999999999 | 1 | 5 | 0 | 0 | 6
+ 2 | 2 | 5 | 1 | 0 | 6
+ 2.00000000000001 | 2 | 4 | 1 | 0 | 6
+ 3 | 2 | 4 | 1 | 0 | 6
+ 4 | 3 | 4 | 2 | 0 | 6
+ 4.5 | 3 | 3 | 2 | 0 | 6
+ 5 | 3 | 3 | 3 | 1 | 7
+ 5.5 | 3 | 3 | 3 | 21 | 7
+ 6 | 4 | 3 | 3 | 21 | 7
+ 7 | 4 | 2 | 4 | 21 | 7
+ 8 | 5 | 2 | 5 | 21 | 7
+ 9 | 5 | 1 | 5 | 21 | 7
+ 9.99999999999999 | 5 | 1 | 5 | 21 | 7
+ 10 | 6 | 1 | 5 | 21 | 8
+ 10.0000000000001 | 6 | 0 | 5 | 21 | 8
+ NaN | 6 | 0 | 5 | 21 | 11
+(20 rows)
+
+DROP TABLE width_bucket_test;
-- TO_CHAR()
--
SELECT '' AS to_char_1, to_char(val, '9G999G999G999G999G999')
SELECT a, ceil(a), ceiling(a), floor(a), round(a) FROM ceil_floor_round;
DROP TABLE ceil_floor_round;
+-- Testing for width_bucket()
+-- NULL result
+SELECT width_bucket(NULL, NULL, NULL, NULL);
+
+-- errors
+SELECT width_bucket(5.0, 3.0, 4.0, 0);
+SELECT width_bucket(5.0, 3.0, 4.0, -5);
+SELECT width_bucket(3.0, 3.0, 3.0, 888);
+
+-- normal operation
+CREATE TABLE width_bucket_test (operand numeric);
+
+COPY width_bucket_test FROM stdin;
+-5.2
+-0.0000000000001
+0.0000000000001
+1
+1.99999999999999
+2
+2.00000000000001
+3
+4
+4.5
+5
+5.5
+6
+7
+8
+9
+9.99999999999999
+10
+10.0000000000001
+NaN
+\.
+
+SELECT
+ operand,
+ width_bucket(operand, 0, 10, 5) AS wb_1,
+ width_bucket(operand, 10, 0, 5) AS wb_2,
+ width_bucket(operand, 2, 8, 4) AS wb_3,
+ width_bucket(operand, 5.0, 5.5, 20) AS wb_4,
+ width_bucket(operand, -25, 25, 10) AS wb_5
+ FROM width_bucket_test;
+
+DROP TABLE width_bucket_test;
+
-- TO_CHAR()
--
SELECT '' AS to_char_1, to_char(val, '9G999G999G999G999G999')
projects / postgresql.git / commitdiff