vn-0003-Avoid-to-handle-FORCE_NOT_NULL-FORCE_NULL-options.patch

From 9b4d44b37414e6471b9452c6a33ff7eb565651e5 Mon Sep 17 00:00:00 2001
From: Mingli Zhang <avamingli@gmail.com>
Date: Tue, 26 Jul 2022 23:38:56 +0800
Subject: [PATCH vn] Avoid to handle FORCE_NOT_NULL/FORCE_NULL options when
 COPY TO.

FORCE_NOT_NULL and FORCE_NULL are only used when COPY FROM.
Remove unnecessary codes when COPY TO.
Add assertions.
---
 src/backend/commands/copyfrom.c |  5 ++++
 src/backend/commands/copyto.c   | 49 ++-------------------------------
 2 files changed, 8 insertions(+), 46 deletions(-)

diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index a976008b3d..086a05ef52 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -1234,6 +1234,11 @@ BeginCopyFrom(ParseState *pstate,
 
 	/* Extract options from the statement node tree */
 	ProcessCopyOptions(pstate, &cstate->opts, true /* is_from */ , options);
+	/* force_null, force_notnull avaliable only in CSV mode */
+	Assert((cstate->opts.force_null != NIL || cstate->opts.force_notnull != NIL) ? cstate->opts.csv_mode : true);
+	/* force_quote can't be used in COPY FROM */
+	Assert(cstate->opts.force_quote == NULL);
+	Assert(!cstate->opts.force_quote_all);
 
 	/* Process the target relation */
 	cstate->rel = rel;
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index fca29a9a10..d7558318a0 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -415,6 +415,9 @@ BeginCopyTo(ParseState *pstate,
 
 	/* Extract options from the statement node tree */
 	ProcessCopyOptions(pstate, &cstate->opts, false /* is_from */ , options);
+	/* force_null and force_notnull can't be used in COPY TO */
+	Assert(cstate->opts.force_null == NULL);
+	Assert(cstate->opts.force_notnull== NULL);
 
 	/* Process the source/target relation or query */
 	if (rel)
@@ -591,52 +594,6 @@ BeginCopyTo(ParseState *pstate,
 		}
 	}
 
-	/* Convert FORCE_NOT_NULL name list to per-column flags, check validity */
-	cstate->opts.force_notnull_flags = (bool *) palloc0(num_phys_attrs * sizeof(bool));
-	if (cstate->opts.force_notnull)
-	{
-		List	   *attnums;
-		ListCell   *cur;
-
-		attnums = CopyGetAttnums(tupDesc, cstate->rel, cstate->opts.force_notnull);
-
-		foreach(cur, attnums)
-		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
-
-			if (!list_member_int(cstate->attnumlist, attnum))
-				ereport(ERROR,
-						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-						 errmsg("FORCE_NOT_NULL column \"%s\" not referenced by COPY",
-								NameStr(attr->attname))));
-			cstate->opts.force_notnull_flags[attnum - 1] = true;
-		}
-	}
-
-	/* Convert FORCE_NULL name list to per-column flags, check validity */
-	cstate->opts.force_null_flags = (bool *) palloc0(num_phys_attrs * sizeof(bool));
-	if (cstate->opts.force_null)
-	{
-		List	   *attnums;
-		ListCell   *cur;
-
-		attnums = CopyGetAttnums(tupDesc, cstate->rel, cstate->opts.force_null);
-
-		foreach(cur, attnums)
-		{
-			int			attnum = lfirst_int(cur);
-			Form_pg_attribute attr = TupleDescAttr(tupDesc, attnum - 1);
-
-			if (!list_member_int(cstate->attnumlist, attnum))
-				ereport(ERROR,
-						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-						 errmsg("FORCE_NULL column \"%s\" not referenced by COPY",
-								NameStr(attr->attname))));
-			cstate->opts.force_null_flags[attnum - 1] = true;
-		}
-	}
-
 	/* Use client encoding when ENCODING option is not specified. */
 	if (cstate->opts.file_encoding < 0)
 		cstate->file_encoding = pg_get_client_encoding();
-- 
2.34.1