Allow statistics to be collected for foreign tables.

ANALYZE now accepts foreign tables and allows the table's FDW to control
how the sample rows are collected.  (But only manual ANALYZEs will touch
foreign tables, for the moment, since among other things it's not very
clear how to handle remote permissions checks in an auto-analyze.)

contrib/file_fdw is extended to support this.

Etsuro Fujita, reviewed by Shigeru Hanada, some further tweaking by me.

8 files changed, 173 insertions, 72 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 9cd6e672ced..17abe48f25e 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -30,6 +30,7 @@
 #include "commands/tablecmds.h"
 #include "commands/vacuum.h"
 #include "executor/executor.h"
+#include "foreign/fdwapi.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parse_oper.h"
@@ -78,14 +79,12 @@ typedef struct AnlIndexData
 int			default_statistics_target = 100;
 
 /* A few variables that don't seem worth passing around as parameters */
-static int	elevel = -1;
-
 static MemoryContext anl_context = NULL;
-
 static BufferAccessStrategy vac_strategy;
 
 
-static void do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh);
+static void do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
+			   AcquireSampleRowsFunc acquirefunc, bool inh, int elevel);
 static void BlockSampler_Init(BlockSampler bs, BlockNumber nblocks,
 				  int samplesize);
 static bool BlockSampler_HasMore(BlockSampler bs);
@@ -96,13 +95,12 @@ static void compute_index_stats(Relation onerel, double totalrows,
 					MemoryContext col_context);
 static VacAttrStats *examine_attribute(Relation onerel, int attnum,
 				  Node *index_expr);
-static int acquire_sample_rows(Relation onerel, HeapTuple *rows,
-					int targrows, double *totalrows, double *totaldeadrows);
-static double random_fract(void);
-static double init_selection_state(int n);
-static double get_next_S(double t, int n, double *stateptr);
+static int	acquire_sample_rows(Relation onerel, int elevel,
+					HeapTuple *rows, int targrows,
+					double *totalrows, double *totaldeadrows,
+					BlockNumber *totalpages);
 static int	compare_rows(const void *a, const void *b);
-static int acquire_inherited_sample_rows(Relation onerel,
+static int	acquire_inherited_sample_rows(Relation onerel, int elevel,
 							  HeapTuple *rows, int targrows,
 							  double *totalrows, double *totaldeadrows);
 static void update_attstats(Oid relid, bool inh,
@@ -118,13 +116,16 @@ void
 analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
 {
 	Relation	onerel;
+	int			elevel;
+	AcquireSampleRowsFunc acquirefunc;
 
-	/* Set up static variables */
+	/* Select logging level */
 	if (vacstmt->options & VACOPT_VERBOSE)
 		elevel = INFO;
 	else
 		elevel = DEBUG2;
 
+	/* Set up static variables */
 	vac_strategy = bstrategy;
 
 	/*
@@ -182,10 +183,40 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
 	}
 
 	/*
-	 * Check that it's a plain table; we used to do this in get_rel_oids() but
-	 * seems safer to check after we've locked the relation.
+	 * Check that it's a plain table or foreign table; we used to do this
+	 * in get_rel_oids() but seems safer to check after we've locked the
+	 * relation.
 	 */
-	if (onerel->rd_rel->relkind != RELKIND_RELATION)
+	if (onerel->rd_rel->relkind == RELKIND_RELATION)
+	{
+		/* Regular table, so we'll use the regular row acquisition function */
+		acquirefunc = acquire_sample_rows;
+	}
+	else if (onerel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+	{
+		/*
+		 * For a foreign table, call the FDW's hook function to see whether it
+		 * supports analysis.
+		 */
+		FdwRoutine *fdwroutine;
+
+		fdwroutine = GetFdwRoutineByRelId(RelationGetRelid(onerel));
+
+		if (fdwroutine->AnalyzeForeignTable != NULL)
+			acquirefunc = fdwroutine->AnalyzeForeignTable(onerel);
+		else
+			acquirefunc = NULL;
+
+		if (acquirefunc == NULL)
+		{
+			ereport(WARNING,
+					(errmsg("skipping \"%s\" --- cannot analyze this foreign table",
+							RelationGetRelationName(onerel))));
+			relation_close(onerel, ShareUpdateExclusiveLock);
+			return;
+		}
+	}
+	else
 	{
 		/* No need for a WARNING if we already complained during VACUUM */
 		if (!(vacstmt->options & VACOPT_VACUUM))
@@ -227,13 +258,13 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
 	/*
 	 * Do the normal non-recursive ANALYZE.
 	 */
-	do_analyze_rel(onerel, vacstmt, false);
+	do_analyze_rel(onerel, vacstmt, acquirefunc, false, elevel);
 
 	/*
 	 * If there are child tables, do recursive ANALYZE.
 	 */
 	if (onerel->rd_rel->relhassubclass)
-		do_analyze_rel(onerel, vacstmt, true);
+		do_analyze_rel(onerel, vacstmt, acquirefunc, true, elevel);
 
 	/*
 	 * Close source relation now, but keep lock so that no one deletes it
@@ -254,9 +285,15 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
 
 /*
  *	do_analyze_rel() -- analyze one relation, recursively or not
+ *
+ * Note that "acquirefunc" is only relevant for the non-inherited case.
+ * If we supported foreign tables in inheritance trees,
+ * acquire_inherited_sample_rows would need to determine the appropriate
+ * acquirefunc for each child table.
  */
 static void
-do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
+do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
+			   AcquireSampleRowsFunc acquirefunc, bool inh, int elevel)
 {
 	int			attr_cnt,
 				tcnt,
@@ -271,6 +308,7 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
 				numrows;
 	double		totalrows,
 				totaldeadrows;
+	BlockNumber totalpages;
 	HeapTuple  *rows;
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
@@ -447,11 +485,17 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
 	 */
 	rows = (HeapTuple *) palloc(targrows * sizeof(HeapTuple));
 	if (inh)
-		numrows = acquire_inherited_sample_rows(onerel, rows, targrows,
+	{
+		numrows = acquire_inherited_sample_rows(onerel, elevel,
+												rows, targrows,
 												&totalrows, &totaldeadrows);
+		totalpages = 0;			/* not needed in this path */
+	}
 	else
-		numrows = acquire_sample_rows(onerel, rows, targrows,
-									  &totalrows, &totaldeadrows);
+		numrows = (*acquirefunc) (onerel, elevel,
+								  rows, targrows,
+								  &totalrows, &totaldeadrows,
+								  &totalpages);
 
 	/*
 	 * Compute the statistics.	Temporary results during the calculations for
@@ -532,7 +576,7 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt, bool inh)
 	 */
 	if (!inh)
 		vac_update_relstats(onerel,
-							RelationGetNumberOfBlocks(onerel),
+							totalpages,
 							totalrows,
 							visibilitymap_count(onerel),
 							hasindex,
@@ -947,8 +991,8 @@ BlockSampler_Next(BlockSampler bs)
 	 * Knuth says to skip the current block with probability 1 - k/K.
 	 * If we are to skip, we should advance t (hence decrease K), and
 	 * repeat the same probabilistic test for the next block.  The naive
-	 * implementation thus requires a random_fract() call for each block
-	 * number.	But we can reduce this to one random_fract() call per
+	 * implementation thus requires an anl_random_fract() call for each block
+	 * number.	But we can reduce this to one anl_random_fract() call per
 	 * selected block, by noting that each time the while-test succeeds,
 	 * we can reinterpret V as a uniform random number in the range 0 to p.
 	 * Therefore, instead of choosing a new V, we just adjust p to be
@@ -963,7 +1007,7 @@ BlockSampler_Next(BlockSampler bs)
 	 * less than k, which means that we cannot fail to select enough blocks.
 	 *----------
 	 */
-	V = random_fract();
+	V = anl_random_fract();
 	p = 1.0 - (double) k / (double) K;
 	while (V < p)
 	{
@@ -988,6 +1032,7 @@ BlockSampler_Next(BlockSampler bs)
  * The actual number of rows selected is returned as the function result.
  * We also estimate the total numbers of live and dead rows in the table,
  * and return them into *totalrows and *totaldeadrows, respectively.
+ * Also, the number of pages in the relation is returned into *totalpages.
  *
  * The returned list of tuples is in order by physical position in the table.
  * (We will rely on this later to derive correlation estimates.)
@@ -1014,8 +1059,10 @@ BlockSampler_Next(BlockSampler bs)
  * density near the start of the table.
  */
 static int
-acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
-					double *totalrows, double *totaldeadrows)
+acquire_sample_rows(Relation onerel, int elevel,
+					HeapTuple *rows, int targrows,
+					double *totalrows, double *totaldeadrows,
+					BlockNumber *totalpages)
 {
 	int			numrows = 0;	/* # rows now in reservoir */
 	double		samplerows = 0; /* total # rows collected */
@@ -1030,6 +1077,7 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 	Assert(targrows > 0);
 
 	totalblocks = RelationGetNumberOfBlocks(onerel);
+	*totalpages = totalblocks;
 
 	/* Need a cutoff xmin for HeapTupleSatisfiesVacuum */
 	OldestXmin = GetOldestXmin(onerel->rd_rel->relisshared, true);
@@ -1037,7 +1085,7 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 	/* Prepare for sampling block numbers */
 	BlockSampler_Init(&bs, totalblocks, targrows);
 	/* Prepare for sampling rows */
-	rstate = init_selection_state(targrows);
+	rstate = anl_init_selection_state(targrows);
 
 	/* Outer loop over blocks to sample */
 	while (BlockSampler_HasMore(&bs))
@@ -1184,7 +1232,8 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 					 * t.
 					 */
 					if (rowstoskip < 0)
-						rowstoskip = get_next_S(samplerows, targrows, &rstate);
+						rowstoskip = anl_get_next_S(samplerows, targrows,
+													&rstate);
 
 					if (rowstoskip <= 0)
 					{
@@ -1192,7 +1241,7 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 						 * Found a suitable tuple, so save it, replacing one
 						 * old tuple at random
 						 */
-						int			k = (int) (targrows * random_fract());
+						int			k = (int) (targrows * anl_random_fract());
 
 						Assert(k >= 0 && k < targrows);
 						heap_freetuple(rows[k]);
@@ -1252,8 +1301,8 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 }
 
 /* Select a random value R uniformly distributed in (0 - 1) */
-static double
-random_fract(void)
+double
+anl_random_fract(void)
 {
 	return ((double) random() + 1) / ((double) MAX_RANDOM_VALUE + 2);
 }
@@ -1266,21 +1315,21 @@ random_fract(void)
  * It is computed primarily based on t, the number of records already read.
  * The only extra state needed between calls is W, a random state variable.
  *
- * init_selection_state computes the initial W value.
+ * anl_init_selection_state computes the initial W value.
  *
- * Given that we've already read t records (t >= n), get_next_S
+ * Given that we've already read t records (t >= n), anl_get_next_S
  * determines the number of records to skip before the next record is
  * processed.
  */
-static double
-init_selection_state(int n)
+double
+anl_init_selection_state(int n)
 {
 	/* Initial value of W (for use when Algorithm Z is first applied) */
-	return exp(-log(random_fract()) / n);
+	return exp(-log(anl_random_fract()) / n);
 }
 
-static double
-get_next_S(double t, int n, double *stateptr)
+double
+anl_get_next_S(double t, int n, double *stateptr)
 {
 	double		S;
 
@@ -1291,7 +1340,7 @@ get_next_S(double t, int n, double *stateptr)
 		double		V,
 					quot;
 
-		V = random_fract();		/* Generate V */
+		V = anl_random_fract();		/* Generate V */
 		S = 0;
 		t += 1;
 		/* Note: "num" in Vitter's code is always equal to t - n */
@@ -1323,7 +1372,7 @@ get_next_S(double t, int n, double *stateptr)
 						tmp;
 
 			/* Generate U and X */
-			U = random_fract();
+			U = anl_random_fract();
 			X = t * (W - 1.0);
 			S = floor(X);		/* S is tentatively set to floor(X) */
 			/* Test if U <= h(S)/cg(X) in the manner of (6.3) */
@@ -1352,7 +1401,7 @@ get_next_S(double t, int n, double *stateptr)
 				y *= numer / denom;
 				denom -= 1;
 			}
-			W = exp(-log(random_fract()) / n);	/* Generate W in advance */
+			W = exp(-log(anl_random_fract()) / n);	/* Generate W in advance */
 			if (exp(log(y) / n) <= (t + X) / t)
 				break;
 		}
@@ -1389,12 +1438,13 @@ compare_rows(const void *a, const void *b)
 /*
  * acquire_inherited_sample_rows -- acquire sample rows from inheritance tree
  *
- * This has the same API as acquire_sample_rows, except that rows are
+ * This has largely the same API as acquire_sample_rows, except that rows are
  * collected from all inheritance children as well as the specified table.
  * We fail and return zero if there are no inheritance children.
  */
 static int
-acquire_inherited_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
+acquire_inherited_sample_rows(Relation onerel, int elevel,
+							  HeapTuple *rows, int targrows,
 							  double *totalrows, double *totaldeadrows)
 {
 	List	   *tableOIDs;
@@ -1431,6 +1481,11 @@ acquire_inherited_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 	/*
 	 * Count the blocks in all the relations.  The result could overflow
 	 * BlockNumber, so we use double arithmetic.
+	 *
+	 * XXX eventually we will probably want to allow child tables that are
+	 * foreign tables.  Since we can't do RelationGetNumberOfBlocks on a
+	 * foreign table, it's not very clear what fraction of the total to assign
+	 * to it here.
 	 */
 	rels = (Relation *) palloc(list_length(tableOIDs) * sizeof(Relation));
 	relblocks = (double *) palloc(list_length(tableOIDs) * sizeof(double));
@@ -1485,13 +1540,16 @@ acquire_inherited_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 				int			childrows;
 				double		trows,
 							tdrows;
+				BlockNumber	tpages;
 
 				/* Fetch a random sample of the child's rows */
 				childrows = acquire_sample_rows(childrel,
+												elevel,
 												rows + numrows,
 												childtargrows,
 												&trows,
-												&tdrows);
+												&tdrows,
+												&tpages);
 
 				/* We may need to convert from child's rowtype to parent's */
 				if (childrows > 0 &&
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a35e338cc87..a4a36045df1 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -3054,7 +3054,7 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 			break;
 		case AT_SetOptions:		/* ALTER COLUMN SET ( options ) */
 		case AT_ResetOptions:	/* ALTER COLUMN RESET ( options ) */
-			ATSimplePermissions(rel, ATT_TABLE | ATT_INDEX);
+			ATSimplePermissions(rel, ATT_TABLE | ATT_INDEX | ATT_FOREIGN_TABLE);
 			/* This command never recurses */
 			pass = AT_PASS_MISC;
 			break;
@@ -5032,10 +5032,11 @@ ATPrepSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE
 	 * allowSystemTableMods to be turned on.
 	 */
 	if (rel->rd_rel->relkind != RELKIND_RELATION &&
-		rel->rd_rel->relkind != RELKIND_INDEX)
+		rel->rd_rel->relkind != RELKIND_INDEX &&
+		rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE)
 		ereport(ERROR,
 				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-				 errmsg("\"%s\" is not a table or index",
+				 errmsg("\"%s\" is not a table, index, or foreign table",
 						RelationGetRelationName(rel))));
 
 	/* Permissions checks */
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index dc2248bc242..844a2912bb5 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1104,7 +1104,7 @@ describeOneTableDetails(const char *schemaname,
 	bool		printTableInitialized = false;
 	int			i;
 	char	   *view_def = NULL;
-	char	   *headers[6];
+	char	   *headers[9];
 	char	  **seq_values = NULL;
 	char	  **modifiers = NULL;
 	char	  **ptr;
@@ -1395,7 +1395,7 @@ describeOneTableDetails(const char *schemaname,
 	if (verbose)
 	{
 		headers[cols++] = gettext_noop("Storage");
-		if (tableinfo.relkind == 'r')
+		if (tableinfo.relkind == 'r' || tableinfo.relkind == 'f')
 			headers[cols++] = gettext_noop("Stats target");
 		/* Column comments, if the relkind supports this feature. */
 		if (tableinfo.relkind == 'r' || tableinfo.relkind == 'v' ||
@@ -1498,7 +1498,7 @@ describeOneTableDetails(const char *schemaname,
 							  false, false);
 
 			/* Statistics target, if the relkind supports this feature */
-			if (tableinfo.relkind == 'r')
+			if (tableinfo.relkind == 'r' || tableinfo.relkind == 'f')
 			{
 				printTableAddCell(&cont, PQgetvalue(res, i, firstvcol + 1),
 								  false, false);
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 975d65584b8..d113adff033 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -409,6 +409,21 @@ static const SchemaQuery Query_for_list_of_tsvf = {
 	NULL
 };
 
+static const SchemaQuery Query_for_list_of_tf = {
+	/* catname */
+	"pg_catalog.pg_class c",
+	/* selcondition */
+	"c.relkind IN ('r', 'f')",
+	/* viscondition */
+	"pg_catalog.pg_table_is_visible(c.oid)",
+	/* namespace */
+	"c.relnamespace",
+	/* result */
+	"pg_catalog.quote_ident(c.relname)",
+	/* qualresult */
+	NULL
+};
+
 static const SchemaQuery Query_for_list_of_views = {
 	/* catname */
 	"pg_catalog.pg_class c",
@@ -2833,7 +2848,7 @@ psql_completion(char *text, int start, int end)
 /* ANALYZE */
 	/* If the previous word is ANALYZE, produce list of tables */
 	else if (pg_strcasecmp(prev_wd, "ANALYZE") == 0)
-		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tables, NULL);
+		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tf, NULL);
 
 /* WHERE */
 	/* Simple case of the word before the where being the table name */
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index 3deee66b413..3c95dec3bc6 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -170,5 +170,8 @@ extern void lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
 extern void analyze_rel(Oid relid, VacuumStmt *vacstmt,
 			BufferAccessStrategy bstrategy);
 extern bool std_typanalyze(VacAttrStats *stats);
+extern double anl_random_fract(void);
+extern double anl_init_selection_state(int n);
+extern double anl_get_next_S(double t, int n, double *stateptr);
 
 #endif   /* VACUUM_H */
diff --git a/src/include/foreign/fdwapi.h b/src/include/foreign/fdwapi.h
index 854f17755c4..6bf3a5e2306 100644
--- a/src/include/foreign/fdwapi.h
+++ b/src/include/foreign/fdwapi.h
@@ -50,20 +50,32 @@ typedef void (*ReScanForeignScan_function) (ForeignScanState *node);
 
 typedef void (*EndForeignScan_function) (ForeignScanState *node);
 
+typedef int (*AcquireSampleRowsFunc) (Relation relation, int elevel,
+									  HeapTuple *rows, int targrows,
+									  double *totalrows,
+									  double *totaldeadrows,
+									  BlockNumber *totalpages);
+
+typedef AcquireSampleRowsFunc (*AnalyzeForeignTable_function) (Relation relation);
+
 
 /*
  * FdwRoutine is the struct returned by a foreign-data wrapper's handler
  * function.  It provides pointers to the callback functions needed by the
  * planner and executor.
  *
- * Currently, all functions must be supplied.  Later there may be optional
- * additions.  It's recommended that the handler initialize the struct with
- * makeNode(FdwRoutine) so that all fields are set to zero.
+ * More function pointers are likely to be added in the future.  Therefore
+ * it's recommended that the handler initialize the struct with
+ * makeNode(FdwRoutine) so that all fields are set to NULL.  This will
+ * ensure that no fields are accidentally left undefined.
  */
 typedef struct FdwRoutine
 {
 	NodeTag		type;
 
+	/*
+	 * These functions are required.
+	 */
 	GetForeignRelSize_function GetForeignRelSize;
 	GetForeignPaths_function GetForeignPaths;
 	GetForeignPlan_function GetForeignPlan;
@@ -72,6 +84,12 @@ typedef struct FdwRoutine
 	IterateForeignScan_function IterateForeignScan;
 	ReScanForeignScan_function ReScanForeignScan;
 	EndForeignScan_function EndForeignScan;
+
+	/*
+	 * These functions are optional.  Set the pointer to NULL for any
+	 * that are not provided.
+	 */
+	AnalyzeForeignTable_function AnalyzeForeignTable;
 } FdwRoutine;
 
 
diff --git a/src/test/regress/expected/foreign_data.out b/src/test/regress/expected/foreign_data.out
index ba86883b867..b3165d59014 100644
--- a/src/test/regress/expected/foreign_data.out
+++ b/src/test/regress/expected/foreign_data.out
@@ -679,12 +679,12 @@ CREATE FOREIGN TABLE ft1 (
 COMMENT ON FOREIGN TABLE ft1 IS 'ft1';
 COMMENT ON COLUMN ft1.c1 IS 'ft1.c1';
 \d+ ft1
-                               Foreign table "public.ft1"
- Column |  Type   | Modifiers |          FDW Options           | Storage  | Description 
---------+---------+-----------+--------------------------------+----------+-------------
- c1     | integer | not null  | ("param 1" 'val1')             | plain    | ft1.c1
- c2     | text    |           | (param2 'val2', param3 'val3') | extended | 
- c3     | date    |           |                                | plain    | 
+                                      Foreign table "public.ft1"
+ Column |  Type   | Modifiers |          FDW Options           | Storage  | Stats target | Description 
+--------+---------+-----------+--------------------------------+----------+--------------+-------------
+ c1     | integer | not null  | ("param 1" 'val1')             | plain    |              | ft1.c1
+ c2     | text    |           | (param2 'val2', param3 'val3') | extended |              | 
+ c3     | date    |           |                                | plain    |              | 
 Server: s0
 FDW Options: (delimiter ',', quote '"', "be quoted" 'value')
 Has OIDs: no
@@ -730,19 +730,22 @@ ERROR:  cannot alter system column "xmin"
 ALTER FOREIGN TABLE ft1 ALTER COLUMN c7 OPTIONS (ADD p1 'v1', ADD p2 'v2'),
                         ALTER COLUMN c8 OPTIONS (ADD p1 'v1', ADD p2 'v2');
 ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 OPTIONS (SET p2 'V2', DROP p1);
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 SET STATISTICS 10000;
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 SET (n_distinct = 100);
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 SET STATISTICS -1;
 \d+ ft1
-                               Foreign table "public.ft1"
- Column |  Type   | Modifiers |          FDW Options           | Storage  | Description 
---------+---------+-----------+--------------------------------+----------+-------------
- c1     | integer | not null  | ("param 1" 'val1')             | plain    | 
- c2     | text    |           | (param2 'val2', param3 'val3') | extended | 
- c3     | date    |           |                                | plain    | 
- c4     | integer |           |                                | plain    | 
- c6     | integer | not null  |                                | plain    | 
- c7     | integer |           | (p1 'v1', p2 'v2')             | plain    | 
- c8     | text    |           | (p2 'V2')                      | extended | 
- c9     | integer |           |                                | plain    | 
- c10    | integer |           | (p1 'v1')                      | plain    | 
+                                      Foreign table "public.ft1"
+ Column |  Type   | Modifiers |          FDW Options           | Storage  | Stats target | Description 
+--------+---------+-----------+--------------------------------+----------+--------------+-------------
+ c1     | integer | not null  | ("param 1" 'val1')             | plain    | 10000        | 
+ c2     | text    |           | (param2 'val2', param3 'val3') | extended |              | 
+ c3     | date    |           |                                | plain    |              | 
+ c4     | integer |           |                                | plain    |              | 
+ c6     | integer | not null  |                                | plain    |              | 
+ c7     | integer |           | (p1 'v1', p2 'v2')             | plain    |              | 
+ c8     | text    |           | (p2 'V2')                      | extended |              | 
+ c9     | integer |           |                                | plain    |              | 
+ c10    | integer |           | (p1 'v1')                      | plain    |              | 
 Server: s0
 FDW Options: (delimiter ',', quote '"', "be quoted" 'value')
 Has OIDs: no
diff --git a/src/test/regress/sql/foreign_data.sql b/src/test/regress/sql/foreign_data.sql
index 0c956727deb..4137969e7de 100644
--- a/src/test/regress/sql/foreign_data.sql
+++ b/src/test/regress/sql/foreign_data.sql
@@ -307,6 +307,9 @@ ALTER FOREIGN TABLE ft1 ALTER COLUMN xmin OPTIONS (ADD p1 'v1'); -- ERROR
 ALTER FOREIGN TABLE ft1 ALTER COLUMN c7 OPTIONS (ADD p1 'v1', ADD p2 'v2'),
                         ALTER COLUMN c8 OPTIONS (ADD p1 'v1', ADD p2 'v2');
 ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 OPTIONS (SET p2 'V2', DROP p1);
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 SET STATISTICS 10000;
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 SET (n_distinct = 100);
+ALTER FOREIGN TABLE ft1 ALTER COLUMN c8 SET STATISTICS -1;
 \d+ ft1
 -- can't change the column type if it's used elsewhere
 CREATE TABLE use_ft1_column_type (x ft1);