Merge pull request #4610 from citusdata/fix_4600

Columnar: Fix lateral joins

src/backend/columnar/cstore_customscan.c

@@ -53,7 +53,8 @@ typedef struct ColumnarScanState
 
 static void ColumnarSetRelPathlistHook(PlannerInfo *root, RelOptInfo *rel, Index rti,
 									   RangeTblEntry *rte);
-static Path * CreateColumnarScanPath(RelOptInfo *rel, RangeTblEntry *rte);
+static Path * CreateColumnarScanPath(PlannerInfo *root, RelOptInfo *rel,
+									 RangeTblEntry *rte);
 static Cost ColumnarScanCost(RangeTblEntry *rte);
 static Plan * ColumnarScanPath_PlanCustomPath(PlannerInfo *root,
 											  RelOptInfo *rel,
@@ -182,7 +183,7 @@ ColumnarSetRelPathlistHook(PlannerInfo *root, RelOptInfo *rel, Index rti,
 							errmsg("sample scans not supported on columnar tables")));
 		}
 
-		Path *customPath = CreateColumnarScanPath(rel, rte);
+		Path *customPath = CreateColumnarScanPath(root, rel, rte);
 
 		ereport(DEBUG1, (errmsg("pathlist hook for columnar table am")));
 
@@ -195,7 +196,7 @@ ColumnarSetRelPathlistHook(PlannerInfo *root, RelOptInfo *rel, Index rti,
 
 
 static Path *
-CreateColumnarScanPath(RelOptInfo *rel, RangeTblEntry *rte)
+CreateColumnarScanPath(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 {
 	ColumnarScanPath *cspath = (ColumnarScanPath *) newNode(sizeof(ColumnarScanPath),
 															T_CustomPath);
@@ -214,6 +215,14 @@ CreateColumnarScanPath(RelOptInfo *rel, RangeTblEntry *rte)
 	path->parent = rel;
 	path->pathtarget = rel->reltarget;
 
+	/*
+	 * We don't support pushing join clauses into the quals of a seqscan, but
+	 * it could still have required parameterization due to LATERAL refs in
+	 * its tlist.
+	 */
+	path->param_info = get_baserel_parampathinfo(root, rel,
+												 rel->lateral_relids);
+
 	/*
 	 * Add cost estimates for a columnar table scan, row count is the rows estimated by
 	 * postgres' planner.

src/test/regress/expected/am_query.out

@@ -1,6 +1,8 @@
 --
--- Test querying cstore_fdw tables.
+-- Test querying columnar tables.
 --
+CREATE SCHEMA columnar_join;
+SET search_path to columnar_join, public;
 -- Settings to make the result deterministic
 SET datestyle = "ISO, YMD";
 -- Query uncompressed data
@@ -119,3 +121,63 @@ INSERT INTO union_second SELECT a, a FROM generate_series(11, 15) a;
 (10 rows)
 
 DROP TABLE union_first, union_second;
+-- https://github.com/citusdata/citus/issues/4600
+CREATE TABLE INT8_TBL_columnar(q1 int8, q2 int8) using columnar;
+INSERT INTO INT8_TBL_columnar VALUES('  123   ','  456');
+INSERT INTO INT8_TBL_columnar VALUES('123   ','4567890123456789');
+INSERT INTO INT8_TBL_columnar VALUES('4567890123456789','123');
+INSERT INTO INT8_TBL_columnar VALUES(+4567890123456789,'4567890123456789');
+INSERT INTO INT8_TBL_columnar VALUES('+4567890123456789','-4567890123456789');
+explain (costs off, summary off) select * from
+  INT8_TBL_columnar a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_columnar b cross join INT8_TBL_columnar c) ss
+  on a.q2 = ss.bq1;
+                          QUERY PLAN
+---------------------------------------------------------------------
+ Nested Loop Left Join
+   ->  Custom Scan (ColumnarScan) on int8_tbl_columnar a
+   ->  Nested Loop
+         ->  Custom Scan (ColumnarScan) on int8_tbl_columnar b
+               Filter: (a.q2 = q1)
+         ->  Custom Scan (ColumnarScan) on int8_tbl_columnar c
+(6 rows)
+
+explain (costs off, summary off)
+  SELECT COUNT(*) FROM INT8_TBL_columnar t1 JOIN
+  LATERAL (SELECT * FROM INT8_TBL_columnar t2 WHERE t1.q1 = t2.q1)
+  as foo ON (true);
+                              QUERY PLAN
+---------------------------------------------------------------------
+ Aggregate
+   ->  Hash Join
+         Hash Cond: (t2.q1 = t1.q1)
+         ->  Custom Scan (ColumnarScan) on int8_tbl_columnar t2
+         ->  Hash
+               ->  Custom Scan (ColumnarScan) on int8_tbl_columnar t1
+(6 rows)
+
+CREATE TABLE INT8_TBL_heap (LIKE INT8_TBL_columnar) ;
+INSERT INTO INT8_TBL_heap SELECT * FROM INT8_TBL_columnar;
+CREATE TABLE result_columnar AS
+select * from
+  INT8_TBL_columnar a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_columnar b cross join INT8_TBL_columnar c) ss
+  on a.q2 = ss.bq1;
+CREATE TABLE result_regular AS
+select * from
+  INT8_TBL_heap a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_heap b cross join INT8_TBL_heap c) ss
+  on a.q2 = ss.bq1;
+-- 2 results should be identical, so the following should be empty
+(table result_columnar EXCEPT table result_regular)
+UNION
+(table result_regular EXCEPT table result_columnar);
+ q1 | q2 | bq1 | cq1 | least
+---------------------------------------------------------------------
+(0 rows)
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA columnar_join CASCADE;

src/test/regress/sql/am_query.sql

@@ -1,7 +1,10 @@
 --
--- Test querying cstore_fdw tables.
+-- Test querying columnar tables.
 --
 
+CREATE SCHEMA columnar_join;
+SET search_path to columnar_join, public;
+
 -- Settings to make the result deterministic
 SET datestyle = "ISO, YMD";
 
@@ -43,3 +46,48 @@ INSERT INTO union_second SELECT a, a FROM generate_series(11, 15) a;
 (SELECT a*1, b FROM union_first) union all (SELECT a*1, b FROM union_second);
 
 DROP TABLE union_first, union_second;
+
+-- https://github.com/citusdata/citus/issues/4600
+CREATE TABLE INT8_TBL_columnar(q1 int8, q2 int8) using columnar;
+
+INSERT INTO INT8_TBL_columnar VALUES('  123   ','  456');
+INSERT INTO INT8_TBL_columnar VALUES('123   ','4567890123456789');
+INSERT INTO INT8_TBL_columnar VALUES('4567890123456789','123');
+INSERT INTO INT8_TBL_columnar VALUES(+4567890123456789,'4567890123456789');
+INSERT INTO INT8_TBL_columnar VALUES('+4567890123456789','-4567890123456789');
+
+explain (costs off, summary off) select * from
+  INT8_TBL_columnar a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_columnar b cross join INT8_TBL_columnar c) ss
+  on a.q2 = ss.bq1;
+
+explain (costs off, summary off)
+  SELECT COUNT(*) FROM INT8_TBL_columnar t1 JOIN
+  LATERAL (SELECT * FROM INT8_TBL_columnar t2 WHERE t1.q1 = t2.q1)
+  as foo ON (true);
+
+CREATE TABLE INT8_TBL_heap (LIKE INT8_TBL_columnar) USING heap;
+INSERT INTO INT8_TBL_heap SELECT * FROM INT8_TBL_columnar;
+
+CREATE TABLE result_columnar AS
+select * from
+  INT8_TBL_columnar a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_columnar b cross join INT8_TBL_columnar c) ss
+  on a.q2 = ss.bq1;
+
+CREATE TABLE result_regular AS
+select * from
+  INT8_TBL_heap a left join lateral
+  (select b.q1 as bq1, c.q1 as cq1, least(a.q1,b.q1,c.q1) from
+   INT8_TBL_heap b cross join INT8_TBL_heap c) ss
+  on a.q2 = ss.bq1;
+
+-- 2 results should be identical, so the following should be empty
+(table result_columnar EXCEPT table result_regular)
+UNION
+(table result_regular EXCEPT table result_columnar);
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA columnar_join CASCADE;