Support for SSSSS datetime format pattern

SQL Standard 2016 defines SSSSS format pattern for seconds past midnight in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause.  In our
datetime parsing engine we currently support it with SSSS name.

This commit adds SSSSS as an alias for SSSS.  Alias is added in favor of
upcoming jsonpath .datetime() method.  But it's also supported in to_date()/
to_timestamp() as positive side effect.

Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Alexander Korotkov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut

doc/src/sgml/func.sgml

@@ -6175,7 +6175,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
         <entry>microsecond (000000-999999)</entry>
        </row>
        <row>
-        <entry><literal>SSSS</literal></entry>
+        <entry><literal>SSSS</literal>, <literal>SSSSS</literal></entry>
         <entry>seconds past midnight (0-86399)</entry>
        </row>
        <row>

src/backend/utils/adt/formatting.c

@@ -626,6 +626,7 @@ typedef enum
 	DCH_PM,
 	DCH_Q,
 	DCH_RM,
+	DCH_SSSSS,
 	DCH_SSSS,
 	DCH_SS,
 	DCH_TZH,
@@ -678,6 +679,7 @@ typedef enum
 	DCH_pm,
 	DCH_q,
 	DCH_rm,
+	DCH_sssss,
 	DCH_ssss,
 	DCH_ss,
 	DCH_tz,
@@ -787,7 +789,8 @@ static const KeyWord DCH_keywords[] = {
 	{"PM", 2, DCH_PM, false, FROM_CHAR_DATE_NONE},
 	{"Q", 1, DCH_Q, true, FROM_CHAR_DATE_NONE}, /* Q */
 	{"RM", 2, DCH_RM, false, FROM_CHAR_DATE_GREGORIAN}, /* R */
-	{"SSSS", 4, DCH_SSSS, true, FROM_CHAR_DATE_NONE},	/* S */
+	{"SSSSS", 5, DCH_SSSS, true, FROM_CHAR_DATE_NONE},	/* S */
+	{"SSSS", 4, DCH_SSSS, true, FROM_CHAR_DATE_NONE},
 	{"SS", 2, DCH_SS, true, FROM_CHAR_DATE_NONE},
 	{"TZH", 3, DCH_TZH, false, FROM_CHAR_DATE_NONE},	/* T */
 	{"TZM", 3, DCH_TZM, true, FROM_CHAR_DATE_NONE},
@@ -839,7 +842,8 @@ static const KeyWord DCH_keywords[] = {
 	{"pm", 2, DCH_pm, false, FROM_CHAR_DATE_NONE},
 	{"q", 1, DCH_Q, true, FROM_CHAR_DATE_NONE}, /* q */
 	{"rm", 2, DCH_rm, false, FROM_CHAR_DATE_GREGORIAN}, /* r */
-	{"ssss", 4, DCH_SSSS, true, FROM_CHAR_DATE_NONE},	/* s */
+	{"sssss", 5, DCH_SSSS, true, FROM_CHAR_DATE_NONE},	/* s */
+	{"ssss", 4, DCH_SSSS, true, FROM_CHAR_DATE_NONE},
 	{"ss", 2, DCH_SS, true, FROM_CHAR_DATE_NONE},
 	{"tz", 2, DCH_tz, false, FROM_CHAR_DATE_NONE},	/* t */
 	{"us", 2, DCH_US, true, FROM_CHAR_DATE_NONE},	/* u */
@@ -920,10 +924,10 @@ static const int DCH_index[KeyWord_INDEX_SIZE] = {
 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 	-1, -1, -1, -1, -1, DCH_A_D, DCH_B_C, DCH_CC, DCH_DAY, -1,
 	DCH_FF1, -1, DCH_HH24, DCH_IDDD, DCH_J, -1, -1, DCH_MI, -1, DCH_OF,
-	DCH_P_M, DCH_Q, DCH_RM, DCH_SSSS, DCH_TZH, DCH_US, -1, DCH_WW, -1, DCH_Y_YYY,
+	DCH_P_M, DCH_Q, DCH_RM, DCH_SSSSS, DCH_TZH, DCH_US, -1, DCH_WW, -1, DCH_Y_YYY,
 	-1, -1, -1, -1, -1, -1, -1, DCH_a_d, DCH_b_c, DCH_cc,
 	DCH_day, -1, DCH_ff1, -1, DCH_hh24, DCH_iddd, DCH_j, -1, -1, DCH_mi,
-	-1, -1, DCH_p_m, DCH_q, DCH_rm, DCH_ssss, DCH_tz, DCH_us, -1, DCH_ww,
+	-1, -1, DCH_p_m, DCH_q, DCH_rm, DCH_sssss, DCH_tz, DCH_us, -1, DCH_ww,
 	-1, DCH_y_yyy, -1, -1, -1, -1
 
 	/*---- chars over 126 are skipped ----*/

src/test/regress/expected/horology.out

@@ -3077,6 +3077,14 @@ SELECT to_timestamp('2015-02-11 86000', 'YYYY-MM-DD SSSS');  -- ok
 
 SELECT to_timestamp('2015-02-11 86400', 'YYYY-MM-DD SSSS');
 ERROR:  date/time field value out of range: "2015-02-11 86400"
+SELECT to_timestamp('2015-02-11 86000', 'YYYY-MM-DD SSSSS');  -- ok
+         to_timestamp         
+------------------------------
+ Wed Feb 11 23:53:20 2015 PST
+(1 row)
+
+SELECT to_timestamp('2015-02-11 86400', 'YYYY-MM-DD SSSSS');
+ERROR:  date/time field value out of range: "2015-02-11 86400"
 SELECT to_date('2016-13-10', 'YYYY-MM-DD');
 ERROR:  date/time field value out of range: "2016-13-10"
 SELECT to_date('2016-02-30', 'YYYY-MM-DD');
@@ -3140,4 +3148,16 @@ SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD HH:MI:SS TZ');
  2012-12-12 12:00:00 -01:30
 (1 row)
 
+SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD SSSS');
+     to_char      
+------------------
+ 2012-12-12 43200
+(1 row)
+
+SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD SSSSS');
+     to_char      
+------------------
+ 2012-12-12 43200
+(1 row)
+
 RESET TIME ZONE;

src/test/regress/sql/horology.sql

@@ -480,6 +480,8 @@ SELECT to_timestamp('2016-02-29 15:50:55', 'YYYY-MM-DD HH24:MI:SS');  -- ok
 SELECT to_timestamp('2015-02-29 15:50:55', 'YYYY-MM-DD HH24:MI:SS');
 SELECT to_timestamp('2015-02-11 86000', 'YYYY-MM-DD SSSS');  -- ok
 SELECT to_timestamp('2015-02-11 86400', 'YYYY-MM-DD SSSS');
+SELECT to_timestamp('2015-02-11 86000', 'YYYY-MM-DD SSSSS');  -- ok
+SELECT to_timestamp('2015-02-11 86400', 'YYYY-MM-DD SSSSS');
 SELECT to_date('2016-13-10', 'YYYY-MM-DD');
 SELECT to_date('2016-02-30', 'YYYY-MM-DD');
 SELECT to_date('2016-02-29', 'YYYY-MM-DD');  -- ok
@@ -503,5 +505,7 @@ SELECT '2012-12-12 12:00'::timestamptz;
 SELECT '2012-12-12 12:00 America/New_York'::timestamptz;
 
 SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD HH:MI:SS TZ');
+SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD SSSS');
+SELECT to_char('2012-12-12 12:00'::timestamptz, 'YYYY-MM-DD SSSSS');
 
 RESET TIME ZONE;