From 10f0530b22d1b06c79be9fef26febebf3b9ec4a5 Mon Sep 17 00:00:00 2001 From: Igor Babaev Date: Sat, 6 Apr 2013 15:36:28 -0700 Subject: Fixed bug mdev-4369. The function was adjusted to be able to aggregate the counters of the merged elements. Before this change it was not possible to guarantee the correctness of the counters passed to the the call-back parameter walk_action. As a result, when some elements of a Unique object were flushed into disk the function passed to merge_walk() as the call-back parameter could return wrong counters of elements. This could lead to building wrong histograms. --- mysql-test/r/statistics.result | 39 ++++++++++++++++++++++++++++++++++++++ mysql-test/t/statistics.test | 43 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) (limited to 'mysql-test') diff --git a/mysql-test/r/statistics.result b/mysql-test/r/statistics.result index 9291b945193..20469c01a2e 100644 --- a/mysql-test/r/statistics.result +++ b/mysql-test/r/statistics.result @@ -1511,4 +1511,43 @@ test t1 a 1 5 0.0000 1.0000 10 DOUBLE_PREC_HB 0000FF3FFF7FFFBFFFFF set histogram_size=default; set histogram_type=default; drop table t1; +# +# Bug mdev-4369: histogram for a column with many distinct values +# +CREATE TABLE t1 (id int); +CREATE TABLE t2 (id int); +INSERT INTO t1 (id) VALUES (1), (1), (1),(1); +INSERT INTO t1 (id) SELECT id FROM t1; +INSERT INTO t1 SELECT id+1 FROM t1; +INSERT INTO t1 SELECT id+2 FROM t1; +INSERT INTO t1 SELECT id+4 FROM t1; +INSERT INTO t1 SELECT id+8 FROM t1; +INSERT INTO t1 SELECT id+16 FROM t1; +INSERT INTO t1 SELECT id+32 FROM t1; +INSERT INTO t1 SELECT id+64 FROM t1; +INSERT INTO t1 SELECT id+128 FROM t1; +INSERT INTO t1 SELECT id+256 FROM t1; +INSERT INTO t1 SELECT id+512 FROM t1; +INSERT INTO t2 SELECT id FROM t1 ORDER BY id*rand(); +SELECT COUNT(*) FROM t2; +COUNT(*) +8192 +SELECT COUNT(DISTINCT id) FROM t2; +COUNT(DISTINCT id) +1024 +set @@tmp_table_size=1024*16; +set @@max_heap_table_size=1024*16; +set histogram_size=63; +analyze table t2 persistent for all; +Table Op Msg_type Msg_text +test.t2 analyze status OK +select db_name, table_name, column_name, +min_value, max_value, +nulls_ratio, avg_frequency, +hist_size, hist_type, HEX(histogram) +FROM mysql.column_stats; +db_name table_name column_name min_value max_value nulls_ratio avg_frequency hist_size hist_type HEX(histogram) +test t2 id 1 1024 0.0000 8.0000 63 SINGLE_PREC_HB 03070B0F13171B1F23272B2F33373B3F43474B4F53575B5F63676B6F73777B7F83878B8F93979B9FA3A7ABAFB3B7BBBFC3C7CBCFD3D7DBDFE3E7EBEFF3F7FB +set histogram_size=default; +drop table t1, t2; set use_stat_tables=@save_use_stat_tables; diff --git a/mysql-test/t/statistics.test b/mysql-test/t/statistics.test index 4d11e11f033..b2a052fd3e8 100644 --- a/mysql-test/t/statistics.test +++ b/mysql-test/t/statistics.test @@ -638,5 +638,48 @@ set histogram_type=default; drop table t1; +--echo # +--echo # Bug mdev-4369: histogram for a column with many distinct values +--echo # + + +CREATE TABLE t1 (id int); +CREATE TABLE t2 (id int); + +INSERT INTO t1 (id) VALUES (1), (1), (1),(1); +INSERT INTO t1 (id) SELECT id FROM t1; +INSERT INTO t1 SELECT id+1 FROM t1; +INSERT INTO t1 SELECT id+2 FROM t1; +INSERT INTO t1 SELECT id+4 FROM t1; +INSERT INTO t1 SELECT id+8 FROM t1; +INSERT INTO t1 SELECT id+16 FROM t1; +INSERT INTO t1 SELECT id+32 FROM t1; +INSERT INTO t1 SELECT id+64 FROM t1; +INSERT INTO t1 SELECT id+128 FROM t1; +INSERT INTO t1 SELECT id+256 FROM t1; +INSERT INTO t1 SELECT id+512 FROM t1; + +INSERT INTO t2 SELECT id FROM t1 ORDER BY id*rand(); + +SELECT COUNT(*) FROM t2; +SELECT COUNT(DISTINCT id) FROM t2; + +set @@tmp_table_size=1024*16; +set @@max_heap_table_size=1024*16; + +set histogram_size=63; + +analyze table t2 persistent for all; + +select db_name, table_name, column_name, + min_value, max_value, + nulls_ratio, avg_frequency, + hist_size, hist_type, HEX(histogram) + FROM mysql.column_stats; + +set histogram_size=default; + +drop table t1, t2; + set use_stat_tables=@save_use_stat_tables; -- cgit v1.2.1