Fix collations for in-memory filtering

Scan keys created for in-memory filtering were using
collation from the hypertable tuple descriptor. Since
the scan keys are meant to be ran on chunk tuples,
switching to using the collation from the chunk tuple
descriptor fixes the issue.

Author: antekresic

.unreleased/pr_7345

@@ -0,0 +1,2 @@
+Fixes: #7342 Fix collation for in-memory tuple filtering
+Thanks: @hackbnw for reporting an issue with collation during tuple filtering

tsl/src/compression/compression_scankey.c

@@ -35,7 +35,6 @@ build_mem_scankeys_from_slot(Oid ht_relid, CompressionSettings *settings, Relati
 	ScanKeyData *scankeys = NULL;
 	int key_index = 0;
 	TupleDesc out_desc = RelationGetDescr(out_rel);
-	TupleDesc in_desc = slot->tts_tupleDescriptor;
 
 	if (bms_is_empty(constraints->key_columns))
 	{
@@ -99,8 +98,8 @@ build_mem_scankeys_from_slot(Oid ht_relid, CompressionSettings *settings, Relati
 							   isnull ? SK_ISNULL : 0,
 							   attno,
 							   BTEqualStrategyNumber,
-							   in_desc->attrs[AttrNumberGetAttrOffset(ht_attno)].atttypid,
-							   in_desc->attrs[AttrNumberGetAttrOffset(ht_attno)].attcollation,
+							   atttypid,
+							   TupleDescAttr(out_desc, AttrNumberGetAttrOffset(attno))->attcollation,
 							   get_opcode(opr),
 							   isnull ? 0 : value);
 	}

tsl/test/expected/compression_conflicts.out

@@ -708,3 +708,43 @@ ERROR:  inserting into compressed chunk with unique constraints disabled
 INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '7', 0.876, 4.123, 'new insert row');
 ERROR:  inserting into compressed chunk with unique constraints disabled
 \set ON_ERROR_STOP 1
+RESET timescaledb.enable_dml_decompression;
+-- gh issue #7342
+CREATE TABLE test_collation (
+        time int8 NOT NULL,
+        device_id int4 NOT NULL,
+        name TEXT NOT NULL,
+        CONSTRAINT test_collation_pkey PRIMARY KEY (time, device_id, name)
+);
+SELECT create_hypertable('test_collation', 'time', chunk_time_interval => 2419200000);
+      create_hypertable       
+------------------------------
+ (11,public,test_collation,t)
+(1 row)
+
+ALTER TABLE test_collation
+SET (
+        timescaledb.compress,
+        timescaledb.compress_segmentby = 'device_id',
+        timescaledb.compress_orderby = 'time DESC, name'
+);
+INSERT INTO "test_collation"
+  ("time", "device_id", "name")
+VALUES
+  (1609477200000, 41, 'val1'),
+  (1609478100000, 41, 'val1')
+ON CONFLICT DO NOTHING;
+SELECT compress_chunk(ch) FROM show_chunks('test_collation') ch;
+INFO:  using tuplesort to scan rows from "_hyper_11_15_chunk" for compression
+              compress_chunk              
+------------------------------------------
+ _timescaledb_internal._hyper_11_15_chunk
+(1 row)
+
+INSERT INTO "test_collation"
+  ("device_id", "time", "name")
+VALUES
+  (41, 1609477200000, 'val1'),
+  (41, 1609478100000, 'val1')
+ON CONFLICT DO NOTHING;
+INFO:  Using index scan with scan keys: index 1, heap 4, memory 2. 

tsl/test/sql/compression_conflicts.sql

@@ -487,3 +487,34 @@ DO NOTHING;
 -- Even a regular insert will fail due to unique constrant checks for dml decompression
 INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '7', 0.876, 4.123, 'new insert row');
 \set ON_ERROR_STOP 1
+
+RESET timescaledb.enable_dml_decompression;
+
+-- gh issue #7342
+CREATE TABLE test_collation (
+        time int8 NOT NULL,
+        device_id int4 NOT NULL,
+        name TEXT NOT NULL,
+        CONSTRAINT test_collation_pkey PRIMARY KEY (time, device_id, name)
+);
+SELECT create_hypertable('test_collation', 'time', chunk_time_interval => 2419200000);
+ALTER TABLE test_collation
+SET (
+        timescaledb.compress,
+        timescaledb.compress_segmentby = 'device_id',
+        timescaledb.compress_orderby = 'time DESC, name'
+);
+INSERT INTO "test_collation"
+  ("time", "device_id", "name")
+VALUES
+  (1609477200000, 41, 'val1'),
+  (1609478100000, 41, 'val1')
+ON CONFLICT DO NOTHING;
+SELECT compress_chunk(ch) FROM show_chunks('test_collation') ch;
+INSERT INTO "test_collation"
+  ("device_id", "time", "name")
+VALUES
+  (41, 1609477200000, 'val1'),
+  (41, 1609478100000, 'val1')
+ON CONFLICT DO NOTHING;
+