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Add tests for unique index creation with Hypercore TAM #7491

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Add tests for unique index creation with Hypercore TAM #7491

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112 changes: 112 additions & 0 deletions tsl/test/expected/hypercore_index_btree.out
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Original file line number Diff line number Diff line change
Expand Up @@ -1062,3 +1062,115 @@ select * from only_nulls_null;
---------+------+--------+----------+-------+------------
(0 rows)

--------------------------------------------------
-- Test unique index creation --
--------------------------------------------------
create table uniquetable (time timestamptz not null, value int);
select create_hypertable('uniquetable', 'time', create_default_indexes => false);
create_hypertable
--------------------------
(7,public,uniquetable,t)
(1 row)

insert into uniquetable values ('2024-01-01 01:00', 1), ('2024-01-01 02:00', 2);
select format('%I.%I', chunk_schema, chunk_name)::regclass as unique_chunk
from timescaledb_information.chunks
where format('%I.%I', hypertable_schema, hypertable_name)::regclass = 'uniquetable'::regclass
order by unique_chunk asc
limit 1 \gset
alter table uniquetable set (timescaledb.compress_orderby='time');
WARNING: there was some uncertainty picking the default segment by for the hypertable: You do not have any indexes on columns that can be used for segment_by and thus we are not using segment_by for compression. Please make sure you are not missing any indexes
NOTICE: default segment by for hypertable "uniquetable" is set to ""
-- Create a non-Hypercore TAM compressed chunk
select * from compress_chunk(:'unique_chunk');
compress_chunk
-----------------------------------------
_timescaledb_internal._hyper_7_19_chunk
(1 row)

-- Should still be a "heap" chunk
select c.relname, a.amname from pg_class c
inner join pg_am a ON (c.relam = a.oid)
where c.oid = :'unique_chunk'::regclass;
relname | amname
-------------------+--------
_hyper_7_19_chunk | heap
(1 row)

insert into uniquetable values ('2024-01-01 01:00', 3);
-- Unique index creation on compressed chunk not supported
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
ERROR: operation not supported on hypertables that have compression enabled
\set ON_ERROR_STOP 1
Comment on lines +1100 to +1105
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Although it does not harm to have this check here, I am not sure what potential bug you wanted to catch here.

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Just to make clear there is a difference and that this error is intact despite supporting unique indexes on Hypercore TAM.

-- Convert the chunk to using Hypercore TAM
alter table :unique_chunk set access method hypercore;
-- Should now be a chunk using Hypercore TAM
select c.relname, a.amname from pg_class c
inner join pg_am a ON (c.relam = a.oid)
where c.oid = :'unique_chunk'::regclass;
relname | amname
-------------------+-----------
_hyper_7_19_chunk | hypercore
(1 row)

select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;
is_compressed_tid | time | value
-------------------+------------------------------+-------
t | Mon Jan 01 01:00:00 2024 PST | 1
f | Mon Jan 01 01:00:00 2024 PST | 3
t | Mon Jan 01 02:00:00 2024 PST | 2
(3 rows)

-- Unique index creation should work but fail on uniqueness check
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
ERROR: could not create unique index "_hyper_7_19_chunk_time_key"
DETAIL: Key ("time")=(Mon Jan 01 01:00:00 2024 PST) is duplicated.
\set ON_ERROR_STOP 1
-- Recompress to get all values in compressed format
select compress_chunk(:'unique_chunk');
compress_chunk
-----------------------------------------
_timescaledb_internal._hyper_7_19_chunk
(1 row)

-- Everything's compressed
select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;
is_compressed_tid | time | value
-------------------+------------------------------+-------
t | Mon Jan 01 01:00:00 2024 PST | 3
t | Mon Jan 01 01:00:00 2024 PST | 1
t | Mon Jan 01 02:00:00 2024 PST | 2
(3 rows)

-- Unique index creation should still fail
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
ERROR: could not create unique index "_hyper_7_19_chunk_time_key"
DETAIL: Key ("time")=(Mon Jan 01 01:00:00 2024 PST) is duplicated.
\set ON_ERROR_STOP 1
-- Delete the conflicting value and unique index creation should succeed
delete from uniquetable where value = 3;
select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;
is_compressed_tid | time | value
-------------------+------------------------------+-------
f | Mon Jan 01 01:00:00 2024 PST | 1
f | Mon Jan 01 02:00:00 2024 PST | 2
(2 rows)

create unique index time_key on uniquetable (time);
explain (costs off)
select * from uniquetable where time = '2024-01-01 01:00';
QUERY PLAN
-----------------------------------------------------------------------------------
Index Scan using _hyper_7_19_chunk_time_key on _hyper_7_19_chunk
Index Cond: ("time" = 'Mon Jan 01 01:00:00 2024 PST'::timestamp with time zone)
(2 rows)

select * from uniquetable where time = '2024-01-01 01:00';
time | value
------------------------------+-------
Mon Jan 01 01:00:00 2024 PST | 1
(1 row)

Comment on lines +1171 to +1176
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Now that you have a unique index, you should probably have tests that tries to insert rows that violate this constraint and demonstrate that it fails.

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Don't we already have those tests?

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There's actually some overlap with these tests and old tests. We might want to reconcile.

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Since it is already covered, I do not think this is necessary for this pull request.

64 changes: 64 additions & 0 deletions tsl/test/sql/hypercore_index_btree.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -402,3 +402,67 @@ select * from nullvalues where only_nulls is null
except
select * from only_nulls_null;

--------------------------------------------------
-- Test unique index creation --
--------------------------------------------------
create table uniquetable (time timestamptz not null, value int);
select create_hypertable('uniquetable', 'time', create_default_indexes => false);
insert into uniquetable values ('2024-01-01 01:00', 1), ('2024-01-01 02:00', 2);

select format('%I.%I', chunk_schema, chunk_name)::regclass as unique_chunk
from timescaledb_information.chunks
where format('%I.%I', hypertable_schema, hypertable_name)::regclass = 'uniquetable'::regclass
order by unique_chunk asc
limit 1 \gset

alter table uniquetable set (timescaledb.compress_orderby='time');

-- Create a non-Hypercore TAM compressed chunk
select * from compress_chunk(:'unique_chunk');

-- Should still be a "heap" chunk
select c.relname, a.amname from pg_class c
inner join pg_am a ON (c.relam = a.oid)
where c.oid = :'unique_chunk'::regclass;

insert into uniquetable values ('2024-01-01 01:00', 3);

-- Unique index creation on compressed chunk not supported
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
\set ON_ERROR_STOP 1

-- Convert the chunk to using Hypercore TAM
alter table :unique_chunk set access method hypercore;

-- Should now be a chunk using Hypercore TAM
select c.relname, a.amname from pg_class c
inner join pg_am a ON (c.relam = a.oid)
where c.oid = :'unique_chunk'::regclass;

select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;

-- Unique index creation should work but fail on uniqueness check
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
\set ON_ERROR_STOP 1

-- Recompress to get all values in compressed format
select compress_chunk(:'unique_chunk');

-- Everything's compressed
select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;

-- Unique index creation should still fail
\set ON_ERROR_STOP 0
create unique index time_key on uniquetable (time);
\set ON_ERROR_STOP 1

-- Delete the conflicting value and unique index creation should succeed
delete from uniquetable where value = 3;
select _timescaledb_debug.is_compressed_tid(ctid), * from :unique_chunk order by time;
create unique index time_key on uniquetable (time);

explain (costs off)
select * from uniquetable where time = '2024-01-01 01:00';
select * from uniquetable where time = '2024-01-01 01:00';
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