Fix index att number calculation

Attribute offset was used by mistake where attribute number was needed causing wrong values to be fetched when scanning compressed chunk index.
timescale · Dec 15, 2022 · 97c05fe · 97c05fe
1 parent b40b1b8
commit 97c05fe
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Showing 3 changed files with 61 additions and 14 deletions.
diff --git a/tsl/src/compression/compression.c b/tsl/src/compression/compression.c
@@ -632,8 +632,8 @@ index_scan_sequence_number(Relation table_rel, Oid index_oid, ScanKeyData *scank
 	if (index_getnext_tid(index_scan, BackwardScanDirection))
 	{
 		result = index_getattr(index_scan->xs_itup,
-							   index_scan->xs_itupdesc->natts -
-								   1, /* Last attribute of the index is sequence number. */
+							   index_scan->xs_itupdesc
+								   ->natts, /* Last attribute of the index is sequence number. */
 							   index_scan->xs_itupdesc,
 							   &is_null);
 		if (is_null)

diff --git a/tsl/test/expected/compression_merge.out b/tsl/test/expected/compression_merge.out
@@ -253,11 +253,28 @@ NOTICE:  adding not-null constraint to column "Time"
 INSERT INTO test5 SELECT t, 1, gen_rand_minstd() FROM generate_series('2018-03-02 1:00'::TIMESTAMPTZ, '2018-03-03 0:59', '1 minute') t;
 -- Compression is set to merge those 24 chunks into 1 24 hour chunk
 ALTER TABLE test5 set (timescaledb.compress, timescaledb.compress_segmentby='i', timescaledb.compress_orderby='"Time"', timescaledb.compress_chunk_time_interval='24 hours');
-SELECT compress_chunk(i) FROM show_chunks('test5') i LIMIT 1;
+SELECT
+  $$
+  SELECT * FROM test5 ORDER BY i, "Time"
+  $$ AS "QUERY" \gset
+SELECT compress_chunk(i) FROM show_chunks('test5') i LIMIT 4;
               compress_chunk              
 ------------------------------------------
  _timescaledb_internal._hyper_9_163_chunk
-(1 row)
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+(4 rows)
+
+-- Make sure sequence numbers are correctly fetched from index.
+SELECT _ts_meta_sequence_num FROM _timescaledb_internal.compress_hyper_10_187_chunk where i = 1;
+ _ts_meta_sequence_num 
+-----------------------
+                    10
+                    20
+                    30
+                    40
+(4 rows)
 
 SELECT schemaname || '.' || indexname AS "INDEXNAME"
 FROM pg_indexes i
@@ -267,10 +284,31 @@ LIMIT 1 \gset
 DROP INDEX :INDEXNAME;
 -- We dropped the index from compressed chunk thats needed to determine sequence numbers
 -- during merge, merging will fallback to doing heap scans and work just fine.
-SELECT
-  $$
-  SELECT * FROM test5 ORDER BY i, "Time"
-  $$ AS "QUERY" \gset
+SELECT compress_chunk(i, true) FROM show_chunks('test5') i LIMIT 5;
+NOTICE:  chunk "_hyper_9_163_chunk" is already compressed
+              compress_chunk              
+------------------------------------------
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+ _timescaledb_internal._hyper_9_163_chunk
+(5 rows)
+
+-- Make sure sequence numbers are correctly fetched from heap.
+SELECT _ts_meta_sequence_num FROM _timescaledb_internal.compress_hyper_10_187_chunk where i = 1;
+ _ts_meta_sequence_num 
+-----------------------
+                    10
+                    20
+                    30
+                    40
+                    50
+                    60
+                    70
+                    80
+(8 rows)
+
 SELECT 'test5' AS "HYPERTABLE_NAME" \gset
 \ir include/compression_test_merge.sql
 -- This file and its contents are licensed under the Timescale License.
@@ -280,7 +318,7 @@ SELECT 'test5' AS "HYPERTABLE_NAME" \gset
 psql:include/compression_test_merge.sql:12: NOTICE:  chunk "_hyper_9_163_chunk" is already compressed
  count_compressed 
 ------------------
-               24
+               17
 (1 row)
 
                                      ?column?                                      | count 

diff --git a/tsl/test/sql/compression_merge.sql b/tsl/test/sql/compression_merge.sql
@@ -105,22 +105,31 @@ INSERT INTO test5 SELECT t, 1, gen_rand_minstd() FROM generate_series('2018-03-0
 -- Compression is set to merge those 24 chunks into 1 24 hour chunk
 ALTER TABLE test5 set (timescaledb.compress, timescaledb.compress_segmentby='i', timescaledb.compress_orderby='"Time"', timescaledb.compress_chunk_time_interval='24 hours');
 
-SELECT compress_chunk(i) FROM show_chunks('test5') i LIMIT 1;
+SELECT
+  $$
+  SELECT * FROM test5 ORDER BY i, "Time"
+  $$ AS "QUERY" \gset
+
+SELECT compress_chunk(i) FROM show_chunks('test5') i LIMIT 4;
+
+-- Make sure sequence numbers are correctly fetched from index.
+SELECT _ts_meta_sequence_num FROM _timescaledb_internal.compress_hyper_10_187_chunk where i = 1;
 
 SELECT schemaname || '.' || indexname AS "INDEXNAME"
 FROM pg_indexes i
 INNER JOIN _timescaledb_catalog.chunk cc ON i.schemaname = cc.schema_name and i.tablename = cc.table_name
 INNER JOIN _timescaledb_catalog.chunk c ON (cc.id = c.compressed_chunk_id)
 LIMIT 1 \gset
 
+
 DROP INDEX :INDEXNAME;
 
 -- We dropped the index from compressed chunk thats needed to determine sequence numbers
 -- during merge, merging will fallback to doing heap scans and work just fine.
-SELECT
-  $$
-  SELECT * FROM test5 ORDER BY i, "Time"
-  $$ AS "QUERY" \gset
+SELECT compress_chunk(i, true) FROM show_chunks('test5') i LIMIT 5;
+
+-- Make sure sequence numbers are correctly fetched from heap.
+SELECT _ts_meta_sequence_num FROM _timescaledb_internal.compress_hyper_10_187_chunk where i = 1;
 
 SELECT 'test5' AS "HYPERTABLE_NAME" \gset
 \ir include/compression_test_merge.sql