Make pg_dump emit ATTACH PARTITION instead of PARTITION OF (reprise)

alvherre · alvherre · commit 33a53130a894 · 2019-06-10T18:56:23.000-04:00
Using PARTITION OF can result in column ordering being changed from the database being dumped, if the partition uses a column layout different from the parent's. It's not pg_dump's job to editorialize on table definitions, so this is not acceptable; back-patch all the way back to pg10, where partitioned tables where introduced. This change also ensures that partitions end up in the correct tablespace, if different from the parent's; this is an oversight in ca41030 (in pg12 only). Partitioned indexes (in pg11) don't have this problem, because they're already created as independent indexes and attached to their parents afterwards. This change also has the advantage that the partition is restorable from the dump (as a standalone table) even if its parent table isn't restored. The original commits (3b23552 in branch master) failed to cover subsidiary column elements correctly, such as NOT NULL constraint and CHECK constraints, as reported by Rushabh Lathia (initially as a failure to restore serial columns). They were reverted. This recapitulation commit fixes those problems. Add some pg_dump tests to verify these things more exhaustively, including constraints with legacy-inheritance tables, which were not tested originally. In branches 10 and 11, add a local constraint to the pg_dump test partition that was added by commit 2d7eeb1 to master. Author: Álvaro Herrera, David Rowley Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/CAKJS1f_1c260nOt_vBJ067AZ3JXptXVRohDVMLEBmudX1YEx-A@mail.gmail.com Discussion: https://postgr.es/m/20190423185007.GA27954@alvherre.pgsql Discussion: https://postgr.es/m/CAGPqQf0iQV=PPOv2Btog9J9AwOQp6HmuVd6SbGTR_v3Zp2XT1w@mail.gmail.com
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
@@ -8631,9 +8631,12 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
  * Normally this is always true, but it's false for dropped columns, as well
  * as those that were inherited without any local definition.  (If we print
  * such a column it will mistakenly get pg_attribute.attislocal set to true.)
- * However, in binary_upgrade mode, we must print all such columns anyway and
- * fix the attislocal/attisdropped state later, so as to keep control of the
- * physical column order.
+ * For partitions, it's always true, because we want the partitions to be
+ * created independently and ATTACH PARTITION used afterwards.
+ *
+ * In binary_upgrade mode, we must print all columns and fix the attislocal/
+ * attisdropped state later, so as to keep control of the physical column
+ * order.
  *
  * This function exists because there are scattered nonobvious places that
  * must be kept in sync with this decision.
@@ -8643,7 +8646,9 @@ shouldPrintColumn(DumpOptions *dopt, TableInfo *tbinfo, int colno)
 {
 	if (dopt->binary_upgrade)
 		return true;
-	return (tbinfo->attislocal[colno] && !tbinfo->attisdropped[colno]);
+	if (tbinfo->attisdropped[colno])
+		return false;
+	return (tbinfo->attislocal[colno] || tbinfo->ispartition);
 }
 
 
@@ -15594,27 +15599,6 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 		if (tbinfo->reloftype && !dopt->binary_upgrade)
 			appendPQExpBuffer(q, " OF %s", tbinfo->reloftype);
 
-		/*
-		 * If the table is a partition, dump it as such; except in the case of
-		 * a binary upgrade, we dump the table normally and attach it to the
-		 * parent afterward.
-		 */
-		if (tbinfo->ispartition && !dopt->binary_upgrade)
-		{
-			TableInfo  *parentRel = tbinfo->parents[0];
-
-			/*
-			 * With partitions, unlike inheritance, there can only be one
-			 * parent.
-			 */
-			if (tbinfo->numParents != 1)
-				fatal("invalid number of parents %d for table \"%s\"",
-					  tbinfo->numParents, tbinfo->dobj.name);
-
-			appendPQExpBuffer(q, " PARTITION OF %s",
-							  fmtQualifiedDumpable(parentRel));
-		}
-
 		if (tbinfo->relkind != RELKIND_MATVIEW)
 		{
 			/* Dump the attributes */
@@ -15629,26 +15613,30 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 				 */
 				if (shouldPrintColumn(dopt, tbinfo, j))
 				{
+					bool		print_default;
+					bool		print_notnull;
+
 					/*
 					 * Default value --- suppress if to be printed separately.
 					 */
-					bool		has_default = (tbinfo->attrdefs[j] != NULL &&
-											   !tbinfo->attrdefs[j]->separate);
+					print_default = (tbinfo->attrdefs[j] != NULL &&
+									 !tbinfo->attrdefs[j]->separate);
 
 					/*
 					 * Not Null constraint --- suppress if inherited, except
-					 * in binary-upgrade case where that won't work.
+					 * if partition, or in binary-upgrade case where that
+					 * won't work.
 					 */
-					bool		has_notnull = (tbinfo->notnull[j] &&
-											   (!tbinfo->inhNotNull[j] ||
-												dopt->binary_upgrade));
+					print_notnull = (tbinfo->notnull[j] &&
+									 (!tbinfo->inhNotNull[j] ||
+									  tbinfo->ispartition || dopt->binary_upgrade));
 
 					/*
-					 * Skip column if fully defined by reloftype or the
-					 * partition parent.
+					 * Skip column if fully defined by reloftype, except in
+					 * binary upgrade
 					 */
-					if ((tbinfo->reloftype || tbinfo->ispartition) &&
-						!has_default && !has_notnull && !dopt->binary_upgrade)
+					if (tbinfo->reloftype && !print_default && !print_notnull &&
+						!dopt->binary_upgrade)
 						continue;
 
 					/* Format properly if not first attr */
@@ -15671,26 +15659,22 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 						 * clean things up later.
 						 */
 						appendPQExpBufferStr(q, " INTEGER /* dummy */");
-						/* Skip all the rest, too */
+						/* and skip to the next column */
 						continue;
 					}
 
 					/*
-					 * Attribute type
-					 *
-					 * In binary-upgrade mode, we always include the type. If
-					 * we aren't in binary-upgrade mode, then we skip the type
-					 * when creating a typed table ('OF type_name') or a
-					 * partition ('PARTITION OF'), since the type comes from
-					 * the parent/partitioned table.
+					 * Attribute type; print it except when creating a typed
+					 * table ('OF type_name'), but in binary-upgrade mode,
+					 * print it in that case too.
 					 */
-					if (dopt->binary_upgrade || (!tbinfo->reloftype && !tbinfo->ispartition))
+					if (dopt->binary_upgrade || !tbinfo->reloftype)
 					{
 						appendPQExpBuffer(q, " %s",
 										  tbinfo->atttypnames[j]);
 					}
 
-					if (has_default)
+					if (print_default)
 					{
 						if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_STORED)
 							appendPQExpBuffer(q, " GENERATED ALWAYS AS (%s) STORED",
@@ -15701,7 +15685,7 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 					}
 
 
-					if (has_notnull)
+					if (print_notnull)
 						appendPQExpBufferStr(q, " NOT NULL");
 
 					/* Add collation if not default for the type */
@@ -15719,12 +15703,18 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 
 			/*
 			 * Add non-inherited CHECK constraints, if any.
+			 *
+			 * For partitions, we need to include check constraints even if
+			 * they're not defined locally, because the ALTER TABLE ATTACH
+			 * PARTITION that we'll emit later expects the constraint to be
+			 * there.  (No need to fix conislocal: ATTACH PARTITION does that)
 			 */
 			for (j = 0; j < tbinfo->ncheck; j++)
 			{
 				ConstraintInfo *constr = &(tbinfo->checkexprs[j]);
 
-				if (constr->separate || !constr->conislocal)
+				if (constr->separate ||
+					(!constr->conislocal && !tbinfo->ispartition))
 					continue;
 
 				if (actual_atts == 0)
@@ -15741,25 +15731,20 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 
 			if (actual_atts)
 				appendPQExpBufferStr(q, "\n)");
-			else if (!((tbinfo->reloftype || tbinfo->ispartition) &&
-					   !dopt->binary_upgrade))
+			else if (!(tbinfo->reloftype && !dopt->binary_upgrade))
 			{
 				/*
-				 * We must have a parenthesized attribute list, even though
-				 * empty, when not using the OF TYPE or PARTITION OF syntax.
+				 * No attributes? we must have a parenthesized attribute list,
+				 * even though empty, when not using the OF TYPE syntax.
 				 */
 				appendPQExpBufferStr(q, " (\n)");
 			}
 
-			if (tbinfo->ispartition && !dopt->binary_upgrade)
-			{
-				appendPQExpBufferChar(q, '\n');
-				appendPQExpBufferStr(q, tbinfo->partbound);
-			}
-
-			/* Emit the INHERITS clause, except if this is a partition. */
-			if (numParents > 0 &&
-				!tbinfo->ispartition &&
+			/*
+			 * Emit the INHERITS clause (not for partitions), except in
+			 * binary-upgrade mode.
+			 */
+			if (numParents > 0 && !tbinfo->ispartition &&
 				!dopt->binary_upgrade)
 			{
 				appendPQExpBufferStr(q, "\nINHERITS (");
@@ -15910,11 +15895,17 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 				}
 			}
 
+			/*
+			 * Add inherited CHECK constraints, if any.
+			 *
+			 * For partitions, they were already dumped, and conislocal
+			 * doesn't need fixing.
+			 */
 			for (k = 0; k < tbinfo->ncheck; k++)
 			{
 				ConstraintInfo *constr = &(tbinfo->checkexprs[k]);
 
-				if (constr->separate || constr->conislocal)
+				if (constr->separate || constr->conislocal || tbinfo->ispartition)
 					continue;
 
 				appendPQExpBufferStr(q, "\n-- For binary upgrade, set up inherited constraint.\n");
@@ -15932,30 +15923,16 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 				appendPQExpBufferStr(q, "::pg_catalog.regclass;\n");
 			}
 
-			if (numParents > 0)
+			if (numParents > 0 && !tbinfo->ispartition)
 			{
-				appendPQExpBufferStr(q, "\n-- For binary upgrade, set up inheritance and partitioning this way.\n");
+				appendPQExpBufferStr(q, "\n-- For binary upgrade, set up inheritance this way.\n");
 				for (k = 0; k < numParents; k++)
 				{
 					TableInfo  *parentRel = parents[k];
 
-					/* In the partitioning case, we alter the parent */
-					if (tbinfo->ispartition)
-						appendPQExpBuffer(q,
-										  "ALTER TABLE ONLY %s ATTACH PARTITION ",
-										  fmtQualifiedDumpable(parentRel));
-					else
-						appendPQExpBuffer(q, "ALTER TABLE ONLY %s INHERIT ",
-										  qualrelname);
-
-					/* Partition needs specifying the bounds */
-					if (tbinfo->ispartition)
-						appendPQExpBuffer(q, "%s %s;\n",
-										  qualrelname,
-										  tbinfo->partbound);
-					else
-						appendPQExpBuffer(q, "%s;\n",
-										  fmtQualifiedDumpable(parentRel));
+					appendPQExpBuffer(q, "ALTER TABLE ONLY %s INHERIT %s;\n",
+									  qualrelname,
+									  fmtQualifiedDumpable(parentRel));
 				}
 			}
 
@@ -15968,6 +15945,27 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 			}
 		}
 
+		/*
+		 * For partitioned tables, emit the ATTACH PARTITION clause.  Note
+		 * that we always want to create partitions this way instead of using
+		 * CREATE TABLE .. PARTITION OF, mainly to preserve a possible column
+		 * layout discrepancy with the parent, but also to ensure it gets the
+		 * correct tablespace setting if it differs from the parent's.
+		 */
+		if (tbinfo->ispartition)
+		{
+			/* With partitions there can only be one parent */
+			if (tbinfo->numParents != 1)
+				fatal("invalid number of parents %d for table \"%s\"",
+					  tbinfo->numParents, tbinfo->dobj.name);
+
+			/* Perform ALTER TABLE on the parent */
+			appendPQExpBuffer(q,
+							  "ALTER TABLE ONLY %s ATTACH PARTITION %s %s;\n",
+							  fmtQualifiedDumpable(parents[0]),
+							  qualrelname, tbinfo->partbound);
+		}
+
 		/*
 		 * In binary_upgrade mode, arrange to restore the old relfrozenxid and
 		 * relminmxid of all vacuumable relations.  (While vacuum.c processes
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -733,7 +733,12 @@
 			\QALTER TABLE ONLY dump_test.measurement ATTACH PARTITION dump_test_second_schema.measurement_y2006m2 \E
 			\QFOR VALUES FROM ('2006-02-01') TO ('2006-03-01');\E\n
 			/xm,
-		like => { binary_upgrade => 1, },
+		like => {
+			%full_runs,
+			role             => 1,
+			section_pre_data => 1,
+			binary_upgrade   => 1,
+		},
 	  },
 
 	'ALTER TABLE test_table CLUSTER ON test_table_pkey' => {
@@ -2283,9 +2288,9 @@
 	'CREATE TABLE measurement PARTITIONED BY' => {
 		create_order => 90,
 		create_sql   => 'CREATE TABLE dump_test.measurement (
-						city_id int not null,
+						city_id serial not null,
 						logdate date not null,
-						peaktemp int,
+						peaktemp int CHECK (peaktemp >= -460),
 						unitsales int
 					   ) PARTITION BY RANGE (logdate);',
 		regexp => qr/^
@@ -2295,7 +2300,8 @@
 			\s+\Qcity_id integer NOT NULL,\E\n
 			\s+\Qlogdate date NOT NULL,\E\n
 			\s+\Qpeaktemp integer,\E\n
-			\s+\Qunitsales integer\E\n
+			\s+\Qunitsales integer,\E\n
+			\s+\QCONSTRAINT measurement_peaktemp_check CHECK ((peaktemp >= '-460'::integer))\E\n
 			\)\n
 			\QPARTITION BY RANGE (logdate);\E\n
 			/xm,
@@ -2307,7 +2313,7 @@
 		},
 	},
 
-	'CREATE TABLE measurement_y2006m2 PARTITION OF' => {
+	'Partition measurement_y2006m2 creation' => {
 		create_order => 91,
 		create_sql =>
 		  'CREATE TABLE dump_test_second_schema.measurement_y2006m2
@@ -2316,19 +2322,21 @@
 						)
 						FOR VALUES FROM (\'2006-02-01\') TO (\'2006-03-01\');',
 		regexp => qr/^
-			\Q-- Name: measurement_y2006m2;\E.*\n
-			\Q--\E\n\n
-			\QCREATE TABLE dump_test_second_schema.measurement_y2006m2 PARTITION OF dump_test.measurement (\E\n
+			\QCREATE TABLE dump_test_second_schema.measurement_y2006m2 (\E\n
+			\s+\Qcity_id integer DEFAULT nextval('dump_test.measurement_city_id_seq'::regclass) NOT NULL,\E\n
+			\s+\Qlogdate date NOT NULL,\E\n
+			\s+\Qpeaktemp integer,\E\n
+			\s+\Qunitsales integer DEFAULT 0,\E\n
+			\s+\QCONSTRAINT measurement_peaktemp_check CHECK ((peaktemp >= '-460'::integer)),\E\n
 			\s+\QCONSTRAINT measurement_y2006m2_unitsales_check CHECK ((unitsales >= 0))\E\n
-			\)\n
-			\QFOR VALUES FROM ('2006-02-01') TO ('2006-03-01');\E\n
+			\);\n
 			/xm,
 		like => {
 			%full_runs,
-			role             => 1,
 			section_pre_data => 1,
+			role             => 1,
+			binary_upgrade   => 1,
 		},
-		unlike => { binary_upgrade => 1, },
 	},
 
 	'CREATE TABLE test_fourth_table_zero_col' => {
@@ -2432,6 +2440,46 @@
 		unlike => { exclude_dump_test_schema => 1, },
 	},
 
+	'CREATE TABLE test_inheritance_parent' => {
+		create_order => 90,
+		create_sql   => 'CREATE TABLE dump_test.test_inheritance_parent (
+						   col1 int NOT NULL,
+						   col2 int CHECK (col2 >= 42)
+						 );',
+		regexp => qr/^
+		\QCREATE TABLE dump_test.test_inheritance_parent (\E\n
+		\s+\Qcol1 integer NOT NULL,\E\n
+		\s+\Qcol2 integer,\E\n
+		\s+\QCONSTRAINT test_inheritance_parent_col2_check CHECK ((col2 >= 42))\E\n
+		\Q);\E\n
+		/xm,
+		like =>
+		  { %full_runs, %dump_test_schema_runs, section_pre_data => 1, },
+		unlike => { exclude_dump_test_schema => 1, },
+	},
+
+	'CREATE TABLE test_inheritance_child' => {
+		create_order => 91,
+		create_sql   => 'CREATE TABLE dump_test.test_inheritance_child (
+						    col1 int NOT NULL,
+						    CONSTRAINT test_inheritance_child CHECK (col2 >= 142857)
+						) INHERITS (dump_test.test_inheritance_parent);',
+		regexp => qr/^
+		\QCREATE TABLE dump_test.test_inheritance_child (\E\n
+		\s+\Qcol1 integer,\E\n
+		\s+\QCONSTRAINT test_inheritance_child CHECK ((col2 >= 142857))\E\n
+		\)\n
+		\QINHERITS (dump_test.test_inheritance_parent);\E\n
+		/xm,
+		like => {
+			%full_runs, %dump_test_schema_runs, section_pre_data => 1,
+		},
+		unlike => {
+			binary_upgrade           => 1,
+			exclude_dump_test_schema => 1,
+		},
+	},
+
 	'CREATE STATISTICS extended_stats_no_options' => {
 		create_order => 97,
 		create_sql   => 'CREATE STATISTICS dump_test.test_ext_stats_no_options
