In contrib/btree_gin, leftmostvalue_interval() does this:
leftmostvalue_interval(void)
{
Interval *v = palloc(sizeof(Interval));
v->time = DT_NOBEGIN;
v->day = 0;
v->month = 0;
return IntervalPGetDatum(v);
}
which is a long way short of the minimum possible interval value.
As a result, a < or <= query using a GIN index on an interval column
may miss values. For example:
CREATE EXTENSION btree_gin;
CREATE TABLE foo (a interval);
INSERT INTO foo VALUES ('-1000000 years');
CREATE INDEX foo_idx ON foo USING gin (a);
SET enable_seqscan = off;
SELECT * FROM foo WHERE a < '1 year';
a
---
(0 rows)
Attached is a patch fixing this by setting all the fields to their
minimum values, which is guaranteed to be less than any other
interval.
Note that this doesn't affect the contents of the index itself, so
reindexing is not necessary.
Regards,
Dean
diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
new file mode 100644
index c50d68c..b09bb8d
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,9 @@ leftmostvalue_interval(void)
{
Interval *v = palloc(sizeof(Interval));
- v->time = DT_NOBEGIN;
- v->day = 0;
- v->month = 0;
+ v->time = PG_INT64_MIN;
+ v->day = PG_INT32_MIN;
+ v->month = PG_INT32_MIN;
return IntervalPGetDatum(v);
}
diff --git a/contrib/btree_gin/expected/interval.out b/contrib/btree_gin/expected/interval.out
new file mode 100644
index 1f6ef54..8bb9806
--- a/contrib/btree_gin/expected/interval.out
+++ b/contrib/btree_gin/expected/interval.out
@@ -3,30 +3,34 @@ CREATE TABLE test_interval (
i interval
);
INSERT INTO test_interval VALUES
+ ( '-178000000 years' ),
( '03:55:08' ),
( '04:55:08' ),
( '05:55:08' ),
( '08:55:08' ),
( '09:55:08' ),
- ( '10:55:08' )
+ ( '10:55:08' ),
+ ( '178000000 years' )
;
CREATE INDEX idx_interval ON test_interval USING gin (i);
SELECT * FROM test_interval WHERE i<'08:55:08'::interval ORDER BY i;
i
--------------------------
+ @ 178000000 years ago
@ 3 hours 55 mins 8 secs
@ 4 hours 55 mins 8 secs
@ 5 hours 55 mins 8 secs
-(3 rows)
+(4 rows)
SELECT * FROM test_interval WHERE i<='08:55:08'::interval ORDER BY i;
i
--------------------------
+ @ 178000000 years ago
@ 3 hours 55 mins 8 secs
@ 4 hours 55 mins 8 secs
@ 5 hours 55 mins 8 secs
@ 8 hours 55 mins 8 secs
-(4 rows)
+(5 rows)
SELECT * FROM test_interval WHERE i='08:55:08'::interval ORDER BY i;
i
@@ -40,12 +44,14 @@ SELECT * FROM test_interval WHERE i>='08
@ 8 hours 55 mins 8 secs
@ 9 hours 55 mins 8 secs
@ 10 hours 55 mins 8 secs
-(3 rows)
+ @ 178000000 years
+(4 rows)
SELECT * FROM test_interval WHERE i>'08:55:08'::interval ORDER BY i;
i
---------------------------
@ 9 hours 55 mins 8 secs
@ 10 hours 55 mins 8 secs
-(2 rows)
+ @ 178000000 years
+(3 rows)
diff --git a/contrib/btree_gin/sql/interval.sql b/contrib/btree_gin/sql/interval.sql
new file mode 100644
index e385158..7a2f3ac
--- a/contrib/btree_gin/sql/interval.sql
+++ b/contrib/btree_gin/sql/interval.sql
@@ -5,12 +5,14 @@ CREATE TABLE test_interval (
);
INSERT INTO test_interval VALUES
+ ( '-178000000 years' ),
( '03:55:08' ),
( '04:55:08' ),
( '05:55:08' ),
( '08:55:08' ),
( '09:55:08' ),
- ( '10:55:08' )
+ ( '10:55:08' ),
+ ( '178000000 years' )
;
CREATE INDEX idx_interval ON test_interval USING gin (i);
