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Improve test coverage for functional dependencies 

The regression tests for functional dependencies were only using clauses
of the form (Var op Const), i.e. with Var on the left side. This adds
a couple of queries with Var on the right, to test other code paths.

It also prints one of the functional dependencies, to test the data type
output function. The functional dependencies are "perfect" with degree
of 1.0 so this should be stable.

Discussion: https://www.postgresql.org/message-id/flat/20200113230008.g67iyk4cs3xbnjju@development
Author: Tomas Vondra
This commit is contained in:
Tomas Vondra 2020-03-14 23:02:55 +01:00
parent 87c9c2571c
commit f9696782c7
2 changed files with 38 additions and 0 deletions
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31
src/test/regress/expected/stats_ext.out
View File

@ -536,6 +536,13 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE
-- create statistics
CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_dependencies;
ANALYZE functional_dependencies;
-- print the detected dependencies
SELECT dependencies FROM pg_stats_ext WHERE statistics_name = 'func_deps_stat';
dependencies
------------------------------------------------------------------------------------------------------------
{"3 => 4": 1.000000, "3 => 6": 1.000000, "4 => 6": 1.000000, "3, 4 => 6": 1.000000, "3, 6 => 4": 1.000000}
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
estimated | actual
-----------+--------
@ -697,6 +704,12 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi
102 | 714
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
estimated | actual
-----------+--------
102 | 714
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
estimated | actual
-----------+--------
@ -709,6 +722,12 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi
1 | 64
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
estimated | actual
-----------+--------
1 | 64
(1 row)
-- create separate functional dependencies
CREATE STATISTICS functional_dependencies_multi_1 (dependencies) ON a, b FROM functional_dependencies_multi;
CREATE STATISTICS functional_dependencies_multi_2 (dependencies) ON c, d FROM functional_dependencies_multi;
@ -719,6 +738,12 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi
714 | 714
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
estimated | actual
-----------+--------
714 | 714
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
estimated | actual
-----------+--------
@ -731,6 +756,12 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi
65 | 64
(1 row)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
estimated | actual
-----------+--------
65 | 64
(1 row)
DROP TABLE functional_dependencies_multi;
-- MCV lists
CREATE TABLE mcv_lists (

7
src/test/regress/sql/stats_ext.sql
View File

@ -318,6 +318,9 @@ CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_depen
ANALYZE functional_dependencies;
-- print the detected dependencies
SELECT dependencies FROM pg_stats_ext WHERE statistics_name = 'func_deps_stat';
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
@ -391,8 +394,10 @@ ANALYZE functional_dependencies_multi;
-- estimates without any functional dependencies
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
-- create separate functional dependencies
CREATE STATISTICS functional_dependencies_multi_1 (dependencies) ON a, b FROM functional_dependencies_multi;
@ -401,8 +406,10 @@ CREATE STATISTICS functional_dependencies_multi_2 (dependencies) ON c, d FROM fu
ANALYZE functional_dependencies_multi;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
DROP TABLE functional_dependencies_multi;