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Fix nested loop joins that involve compressed chunks #2851

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merged 1 commit into from Jan 27, 2021
Merged

Fix nested loop joins that involve compressed chunks #2851

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1 change: 1 addition & 0 deletions CHANGELOG.md
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Expand Up @@ -9,6 +9,7 @@ accidentally triggering the load of a previous DB version.**
**Bugfixes**
* #2842 Do not mark job as started when seting next_start field
* #2845 Fix continuous aggregate privileges during upgrade
* #2851 Fix nested loop joins that involve compressed chunks
* #2865 Apply volatile function quals at decompresschunk node

**Minor features**
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14 changes: 5 additions & 9 deletions tsl/src/nodes/decompress_chunk/decompress_chunk.c
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Expand Up @@ -681,11 +681,13 @@ typedef struct EMCreationContext
FormData_hypertable_compression *current_col_info;
} EMCreationContext;

/* get the segmentby compression info for an EquivalenceMember (EM) expr,
/* get the compression info for an EquivalenceMember (EM) expr,
* or return NULL if it's not one we can create an EM for
* This is applicable to segment by and compressed columns
* of the compressed table.
*/
static FormData_hypertable_compression *
segmentby_compression_info_for_em(Node *node, EMCreationContext *context)
get_compression_info_for_em(Node *node, EMCreationContext *context)
{
/* based on adjust_appendrel_attrs_mutator */
if (node == NULL)
Expand Down Expand Up @@ -714,10 +716,6 @@ segmentby_compression_info_for_em(Node *node, EMCreationContext *context)
if (col_info == NULL)
return NULL;

/* we can only add EMs for segmentby columns */
if (col_info->segmentby_column_index <= 0)
return NULL;

return col_info;
}

Expand All @@ -734,7 +732,6 @@ create_var_for_compressed_equivalence_member(Var *var, const EMCreationContext *
{
/* based on adjust_appendrel_attrs_mutator */
Assert(context->current_col_info != NULL);
Assert(context->current_col_info->segmentby_column_index > 0);
Assert(var->varno == context->uncompressed_relid_idx);
Assert(var->varattno > 0);

Expand Down Expand Up @@ -787,8 +784,7 @@ add_segmentby_to_equivalence_class(EquivalenceClass *cur_ec, CompressionInfo *in
* be set on the em */
Assert(bms_overlap(cur_em->em_relids, uncompressed_chunk_relids));

context->current_col_info =
segmentby_compression_info_for_em((Node *) cur_em->em_expr, context);
context->current_col_info = get_compression_info_for_em((Node *) cur_em->em_expr, context);
if (context->current_col_info == NULL)
continue;

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145 changes: 145 additions & 0 deletions tsl/test/expected/transparent_decompression_ordered_index-11.out
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Expand Up @@ -567,6 +567,151 @@ ORDER BY time;
SET enable_mergejoin = TRUE;
SET enable_hashjoin = TRUE;
--end github issue 1558
-- github issue 2673
-- nested loop join with parameterized path
-- join condition has a segment by column and another column.
SET enable_hashjoin = false;
SET enable_mergejoin=false;
SET enable_material = false;
SET enable_seqscan = false;
-- restrict so that we select only 1 chunk.
:PREFIX
WITH lookup as ( SELECT * from (values( 3, 5) , (3, 4) ) as lu( did, version) )
SELECT met.*, lookup.*
FROM metrics_ordered_idx met join lookup
ON met.device_id = lookup.did and met.v0 = lookup.version
WHERE met.time > '2000-01-19 19:00:00-05'
and met.time < '2000-01-20 20:00:00-05';
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (actual rows=2 loops=1)
CTE lookup
-> Values Scan on "*VALUES*" (actual rows=2 loops=1)
-> CTE Scan on lookup (actual rows=2 loops=1)
-> Append (actual rows=1 loops=2)
-> Custom Scan (DecompressChunk) on _hyper_1_3_chunk met (actual rows=1 loops=2)
Filter: (("time" > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND ("time" < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone) AND (lookup.version = v0))
Rows Removed by Filter: 47
-> Index Scan using compress_hyper_2_8_chunk__compressed_hypertable_2_device_id__ts on compress_hyper_2_8_chunk (actual rows=1 loops=2)
Index Cond: (device_id = lookup.did)
Filter: ((_ts_meta_max_1 > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND (_ts_meta_min_1 < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone))
(11 rows)

--add filter to segment by (device_id) and compressed attr column (v0)
:PREFIX
WITH lookup as ( SELECT * from (values( 3, 5) , (3, 4) ) as lu( did, version) )
SELECT met.*, lookup.*
FROM metrics_ordered_idx met join lookup
ON met.device_id = lookup.did and met.v0 = lookup.version
WHERE met.time > '2000-01-19 19:00:00-05'
and met.time < '2000-01-20 20:00:00-05'
and met.device_id = 3 and met.v0 = 5;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (actual rows=1 loops=1)
CTE lookup
-> Values Scan on "*VALUES*" (actual rows=2 loops=1)
-> CTE Scan on lookup (actual rows=1 loops=1)
Filter: ((did = 3) AND (version = 5))
Rows Removed by Filter: 1
-> Append (actual rows=1 loops=1)
-> Custom Scan (DecompressChunk) on _hyper_1_3_chunk met (actual rows=1 loops=1)
Filter: (("time" > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND ("time" < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone) AND (v0 = 5))
Rows Removed by Filter: 47
-> Index Scan using compress_hyper_2_8_chunk__compressed_hypertable_2_device_id__ts on compress_hyper_2_8_chunk (actual rows=1 loops=1)
Index Cond: (device_id = 3)
Filter: ((_ts_meta_max_1 > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND (_ts_meta_min_1 < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone))
(13 rows)

:PREFIX
WITH lookup as ( SELECT * from (values( 3, 5) , (3, 4) ) as lu( did, version) )
SELECT met.*, lookup.*
FROM metrics_ordered_idx met join lookup
ON met.device_id = lookup.did and met.v0 = lookup.version
WHERE met.time = '2000-01-19 19:00:00-05'
and met.device_id = 3
and met.device_id_peer = 3 and met.v0 = 5;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (actual rows=0 loops=1)
CTE lookup
-> Values Scan on "*VALUES*" (actual rows=2 loops=1)
-> CTE Scan on lookup (actual rows=1 loops=1)
Filter: ((did = 3) AND (version = 5))
Rows Removed by Filter: 1
-> Append (actual rows=0 loops=1)
-> Custom Scan (DecompressChunk) on _hyper_1_3_chunk met (actual rows=0 loops=1)
Filter: ((v0 = 5) AND ("time" = 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone))
Rows Removed by Filter: 48
-> Index Scan using compress_hyper_2_8_chunk__compressed_hypertable_2_device_id_pee on compress_hyper_2_8_chunk (actual rows=1 loops=1)
Index Cond: (device_id_peer = 3)
Filter: ((device_id = 3) AND (_ts_meta_min_1 <= 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND (_ts_meta_max_1 >= 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone))
(13 rows)

-- lateral subquery
:PREFIX
WITH f1 as ( SELECT * from (values( 7, 5, 4) , (4, 5, 5) ) as lu( device_id, device_id_peer, v0) )
SELECT * FROM metrics_ordered_idx met
JOIN LATERAL
( SELECT node, f1.* from nodetime , f1
WHERE node = f1.device_id) q
ON met.device_id = q.node and met.device_id_peer = q.device_id_peer
and met.v0 = q.v0 and met.v0 > 2 and time = '2018-01-19 20:00:00-05';
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (actual rows=1 loops=1)
Join Filter: (nodetime.node = met.device_id)
CTE f1
-> Values Scan on "*VALUES*" (actual rows=2 loops=1)
-> Nested Loop (actual rows=1 loops=1)
Join Filter: (nodetime.node = f1.device_id)
Rows Removed by Join Filter: 1
-> Seq Scan on nodetime (actual rows=1 loops=1)
-> CTE Scan on f1 (actual rows=2 loops=1)
-> Append (actual rows=1 loops=1)
-> Custom Scan (DecompressChunk) on _hyper_1_4_chunk met (actual rows=1 loops=1)
Filter: ((v0 > 2) AND ("time" = 'Fri Jan 19 17:00:00 2018 PST'::timestamp with time zone) AND (f1.device_id = device_id) AND (f1.v0 = v0))
Rows Removed by Filter: 47
-> Index Scan using compress_hyper_2_9_chunk__compressed_hypertable_2_device_id_pee on compress_hyper_2_9_chunk (actual rows=1 loops=1)
Index Cond: (device_id_peer = f1.device_id_peer)
Filter: ((_ts_meta_min_1 <= 'Fri Jan 19 17:00:00 2018 PST'::timestamp with time zone) AND (_ts_meta_max_1 >= 'Fri Jan 19 17:00:00 2018 PST'::timestamp with time zone) AND (f1.device_id = device_id))
(16 rows)

-- filter on compressed attr (v0) with seqscan enabled and indexscan
-- disabled. filters on compressed attr should be above the seq scan.
SET enable_seqscan = true;
SET enable_indexscan = false;
:PREFIX
WITH lookup as ( SELECT * from (values( 3, 5) , (3, 4) ) as lu( did, version) )
SELECT met.*, lookup.*
FROM metrics_ordered_idx met join lookup
ON met.device_id = lookup.did and met.v0 = lookup.version
and met.device_id = 3
WHERE met.time > '2000-01-19 19:00:00-05'
and met.time < '2000-01-20 20:00:00-05'
and met.device_id = 3
and met.device_id_peer = 3 and met.v0 = 5;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (actual rows=1 loops=1)
CTE lookup
-> Values Scan on "*VALUES*" (actual rows=2 loops=1)
-> CTE Scan on lookup (actual rows=1 loops=1)
Filter: ((did = 3) AND (version = 5))
Rows Removed by Filter: 1
-> Append (actual rows=1 loops=1)
-> Custom Scan (DecompressChunk) on _hyper_1_3_chunk met (actual rows=1 loops=1)
Filter: (("time" > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND ("time" < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone) AND (v0 = 5))
Rows Removed by Filter: 47
-> Seq Scan on compress_hyper_2_8_chunk (actual rows=1 loops=1)
Filter: ((_ts_meta_max_1 > 'Wed Jan 19 16:00:00 2000 PST'::timestamp with time zone) AND (_ts_meta_min_1 < 'Thu Jan 20 17:00:00 2000 PST'::timestamp with time zone) AND (device_id = 3) AND (device_id_peer = 3))
(12 rows)

RESET enable_hashjoin ;
RESET enable_mergejoin;
RESET enable_material ;
RESET enable_indexscan ;
--end github issue 2673
SET enable_seqscan = TRUE;
\ir include/transparent_decompression_constraintaware.sql
-- This file and its contents are licensed under the Timescale License.
Expand Down