Add prefix operator for TEXT type.

The prefix operator along with SP-GiST indexes can be used as an alternative
for LIKE 'word%' commands  and it doesn't have a limitation of string/prefix
length as B-Tree has.

Bump catalog version

Author: Ildus Kurbangaliev with some editorization by me
Review by: Arthur Zakirov, Alexander Korotkov, and me
Discussion: https://www.postgresql.org/message-id/flat/[email protected]

6 files changed, 16 insertions, 4 deletions

diff --git a/src/include/access/stratnum.h b/src/include/access/stratnum.h
index bddfac4c104..0db11a11179 100644
--- a/src/include/access/stratnum.h
+++ b/src/include/access/stratnum.h
@@ -68,8 +68,9 @@ typedef uint16 StrategyNumber;
 #define RTSubEqualStrategyNumber		25	/* for inet <<= */
 #define RTSuperStrategyNumber			26	/* for inet << */
 #define RTSuperEqualStrategyNumber		27	/* for inet >>= */
+#define RTPrefixStrategyNumber			28	/* for text ^@ */
 
-#define RTMaxStrategyNumber				27
+#define RTMaxStrategyNumber				28
 
 
 #endif							/* STRATNUM_H */
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index b2806e6595a..5d55890b9dd 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201803311
+#define CATALOG_VERSION_NO	201804031
 
 #endif
diff --git a/src/include/catalog/pg_amop.h b/src/include/catalog/pg_amop.h
index 03af581df4e..00e77d4c61e 100644
--- a/src/include/catalog/pg_amop.h
+++ b/src/include/catalog/pg_amop.h
@@ -799,6 +799,7 @@ DATA(insert (	4017   25 25 11 s	664 4000 0 ));
 DATA(insert (	4017   25 25 12 s	665 4000 0 ));
 DATA(insert (	4017   25 25 14 s	667 4000 0 ));
 DATA(insert (	4017   25 25 15 s	666 4000 0 ));
+DATA(insert (	4017   25 25 28 s	3877 4000 0 ));
 
 /*
  * btree jsonb_ops
diff --git a/src/include/catalog/pg_operator.h b/src/include/catalog/pg_operator.h
index e74f963eb50..6a6f708914c 100644
--- a/src/include/catalog/pg_operator.h
+++ b/src/include/catalog/pg_operator.h
@@ -134,6 +134,8 @@ DESCR("less than");
 DATA(insert OID =  98 ( "="		   PGNSP PGUID b t t	25	25	16	98 531 texteq eqsel eqjoinsel ));
 DESCR("equal");
 #define TextEqualOperator	98
+DATA(insert OID =  3877 ( "^@"	   PGNSP PGUID b f f	25	25	16	0 0 starts_with prefixsel prefixjoinsel ));
+DESCR("starts with");
 
 DATA(insert OID = 349 (  "||"	   PGNSP PGUID b f f 2277 2283 2277 0 0 array_append   -	   -	 ));
 DESCR("append element onto end of array");
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 90d994c71a4..9bf20c059bc 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -209,6 +209,7 @@ DATA(insert OID =  64 (  int2lt			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16
 DATA(insert OID =  65 (  int4eq			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "23 23" _null_ _null_ _null_ _null_ _null_ int4eq _null_ _null_ _null_ ));
 DATA(insert OID =  66 (  int4lt			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "23 23" _null_ _null_ _null_ _null_ _null_ int4lt _null_ _null_ _null_ ));
 DATA(insert OID =  67 (  texteq			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "25 25" _null_ _null_ _null_ _null_ _null_ texteq _null_ _null_ _null_ ));
+DATA(insert OID =  3696 ( starts_with	   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "25 25" _null_ _null_ _null_ _null_ _null_ text_starts_with _null_ _null_ _null_ ));
 DATA(insert OID =  68 (  xideq			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "28 28" _null_ _null_ _null_ _null_ _null_ xideq _null_ _null_ _null_ ));
 DATA(insert OID = 3308 (  xidneq		   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "28 28" _null_ _null_ _null_ _null_ _null_ xidneq _null_ _null_ _null_ ));
 DATA(insert OID =  69 (  cideq			   PGNSP PGUID 12 1 0 0 0 f f t t f i s 2 0 16 "29 29" _null_ _null_ _null_ _null_ _null_ cideq _null_ _null_ _null_ ));
@@ -2584,6 +2585,10 @@ DATA(insert OID = 1828 ( nlikejoinsel		PGNSP PGUID 12 1 0 0 0 f f f t f s s 5 0
 DESCR("join selectivity of NOT LIKE");
 DATA(insert OID = 1829 ( icregexnejoinsel	PGNSP PGUID 12 1 0 0 0 f f f t f s s 5 0 701 "2281 26 2281 21 2281" _null_ _null_ _null_ _null_  _null_ icregexnejoinsel _null_ _null_ _null_ ));
 DESCR("join selectivity of case-insensitive regex non-match");
+DATA(insert OID = 3437 ( prefixsel			PGNSP PGUID 12 1 0 0 0 f f f t f s s 4 0 701 "2281 26 2281 23" _null_ _null_ _null_ _null_ _null_ prefixsel _null_ _null_ _null_ ));
+DESCR("restriction selectivity of exact prefix");
+DATA(insert OID = 3438 ( prefixjoinsel		PGNSP PGUID 12 1 0 0 0 f f f t f s s 5 0 701 "2281 26 2281 21 2281" _null_ _null_ _null_ _null_  _null_ prefixjoinsel _null_ _null_ _null_ ));
+DESCR("join selectivity of exact prefix");
 
 /* Aggregate-related functions */
 DATA(insert OID = 1830 (  float8_avg	   PGNSP PGUID 12 1 0 0 0 f f f t f i s 1 0 701 "1022" _null_ _null_ _null_ _null_ _null_ float8_avg _null_ _null_ _null_ ));
diff --git a/src/include/utils/selfuncs.h b/src/include/utils/selfuncs.h
index 299c9f846ac..95e44280c4c 100644
--- a/src/include/utils/selfuncs.h
+++ b/src/include/utils/selfuncs.h
@@ -87,8 +87,11 @@ typedef struct VariableStatData
 
 typedef enum
 {
-	Pattern_Type_Like, Pattern_Type_Like_IC,
-	Pattern_Type_Regex, Pattern_Type_Regex_IC
+	Pattern_Type_Like,
+	Pattern_Type_Like_IC,
+	Pattern_Type_Regex,
+	Pattern_Type_Regex_IC,
+	Pattern_Type_Prefix
 } Pattern_Type;
 
 typedef enum