[BACKPORT to 2.4] [#6749] YSQL: Add support for FETCH NEXT, FORWARD, …

…and positive row-count options Summary: Turn ON options NEXT, FORWARD, and positive row-count Test Plan: Jenkins: rebase: 2.4 Reviewers: mihnea Reviewed By: mihnea Subscribers: yql, kannan Differential Revision: https://phabricator.dev.yugabyte.com/D10376
yugabyte · Jan 16, 2021 · 0f567b0 · 0f567b0
1 parent 1c6d4aa
commit 0f567b0
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Showing 4 changed files with 641 additions and 173 deletions.
diff --git a/src/postgres/src/backend/parser/gram.y b/src/postgres/src/backend/parser/gram.y
@@ -7369,8 +7369,6 @@ fetch_args:	cursor_name
 				}
 			| NEXT opt_from_in cursor_name
 				{
-					parser_ybc_signal_unsupported(@1, "FETCH NEXT", 6514);
-
 					FetchStmt *n = makeNode(FetchStmt);
 					n->portalname = $3;
 					n->direction = FETCH_FORWARD;
@@ -7429,8 +7427,9 @@ fetch_args:	cursor_name
 				}
 			| SignedIconst opt_from_in cursor_name
 				{
-					parser_ybc_signal_unsupported(@1, "FETCH + OR -", 6514);
-
+					if ($1 < 0) {
+						parser_ybc_signal_unsupported(@1, "FETCH -", 6514);
+					}
 					FetchStmt *n = makeNode(FetchStmt);
 					n->portalname = $3;
 					n->direction = FETCH_FORWARD;
@@ -7447,8 +7446,6 @@ fetch_args:	cursor_name
 				}
 			| FORWARD opt_from_in cursor_name
 				{
-					parser_ybc_signal_unsupported(@1, "FETCH FORWARD", 6514);
-
 					FetchStmt *n = makeNode(FetchStmt);
 					n->portalname = $3;
 					n->direction = FETCH_FORWARD;
@@ -7457,8 +7454,9 @@ fetch_args:	cursor_name
 				}
 			| FORWARD SignedIconst opt_from_in cursor_name
 				{
-					parser_ybc_signal_unsupported(@1, "FETCH FORWARD", 6514);
-
+					if ($2 < 0) {
+						parser_ybc_signal_unsupported(@1, "FETCH FORWARD -", 6514);
+					}
 					FetchStmt *n = makeNode(FetchStmt);
 					n->portalname = $4;
 					n->direction = FETCH_FORWARD;
@@ -7467,8 +7465,6 @@ fetch_args:	cursor_name
 				}
 			| FORWARD ALL opt_from_in cursor_name
 				{
-					parser_ybc_signal_unsupported(@1, "FETCH FORWARD", 6514);
-
 					FetchStmt *n = makeNode(FetchStmt);
 					n->portalname = $4;
 					n->direction = FETCH_FORWARD;