-- Regression test for adding a value with a count exceeding BUFFER_SIZE in
-- tdigest_add_double_values_count.
--
-- Adding the values one by one would mean too many compactions, so counts
-- larger than the buffer (BUFFER_SIZE = 10 * compression, i.e. 100 for the
-- smallest compression) are added as pre-generated centroids instead. Both
-- paths have to produce comparable results.
-- a single distinct value, so the result is exact on both sides of the
-- BUFFER_SIZE threshold
SELECT tdigest_percentile_of(v, 100::bigint, 10, 1.0) FROM (VALUES (1.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
                   0.5
(1 row)

SELECT tdigest_percentile_of(v, 101::bigint, 10, 1.0) FROM (VALUES (1.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
                   0.5
(1 row)

SELECT tdigest_percentile_of(v, 1000000::bigint, 10, 1.0) FROM (VALUES (1.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
                   0.5
(1 row)

-- two distinct values, with the counts just below and just above the
-- threshold
SELECT tdigest_percentile_of(v, 100::bigint, 10, 2.0) FROM (VALUES (1.0), (2.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
                 0.775
(1 row)

SELECT tdigest_percentile_of(v, 101::bigint, 10, 2.0) FROM (VALUES (1.0), (2.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
                  0.75
(1 row)

-- a larger compression means a larger buffer, so the very same count now
-- goes through the one-by-one path
SELECT tdigest_percentile_of(v, 101::bigint, 100, 2.0) FROM (VALUES (1.0), (2.0)) AS t(v);
 tdigest_percentile_of 
-----------------------
     0.784653465346535
(1 row)