revision-id: 5ca99340105ea9e7d74ef35e6a90839786d862d6 (mariadb-5.5.67-4-g5ca9934) parent(s): be77fa914c30e92e33e60feb5a3e098c765798af author: Igor Babaev committer: Igor Babaev timestamp: 2020-03-12 23:50:20 -0700 message: MDEV-21932 A fast plan with ROR index-merge is ignored when 'index_merge_sort_union=off' When index_merge_sort_union is set to 'off' and index_merge_union is set to 'on' then any evaluated index merge scan must consist only of ROR scans. The cheapest out of such index merges must be chosen. This index merge might not be the cheapest index merge. --- mysql-test/r/index_merge_myisam.result | 52 ++++++++++++++++++++++++++++++++ mysql-test/r/range_vs_index_merge.result | 2 +- mysql-test/t/index_merge_myisam.test | 48 +++++++++++++++++++++++++++++ sql/opt_range.cc | 7 +++++ 4 files changed, 108 insertions(+), 1 deletion(-) diff --git a/mysql-test/r/index_merge_myisam.result b/mysql-test/r/index_merge_myisam.result index 0917190..0720dce 100644 --- a/mysql-test/r/index_merge_myisam.result +++ b/mysql-test/r/index_merge_myisam.result @@ -1704,3 +1704,55 @@ id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,c1,i,c2 NULL NULL NULL 69 Using where DROP TABLE t1; set optimizer_switch= @optimizer_switch_save; +# +# MDEV-21932: ROR union with index_merge_sort_union=off +# +create table t0 (a int); +insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); +insert into t0 select a+10 from t0; +insert into t0 select a+20 from t0; +insert into t0 select a+40 from t0; +insert into t0 select a+80 from t0; +insert into t0 select a+160 from t0; +delete from t0 where a > 300; +create table t1 ( +f1 int, f2 int, f3 int, f4 int, +primary key (f1), key (f3), key(f4) +) engine=myisam; +insert into t1 select a+100, a+100, a+100, a+100 from t0; +insert into t1 VALUES (9,0,2,6), (9930,0,0,NULL); +analyze table t1; +Table Op Msg_type Msg_text +test.t1 analyze status OK +set optimizer_switch='index_merge_sort_union=off'; +set optimizer_switch='index_merge_union=on'; +explain select * from t1 +where (( f3 = 1 or f1 = 7 ) and f1 < 10) or +(f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t1 index_merge PRIMARY,f3,f4 f3,PRIMARY,f3 5,4,5 NULL 3 Using union(f3,PRIMARY,f3); Using where +select * from t1 +where (( f3 = 1 or f1 = 7 ) and f1 < 10) or +(f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +f1 f2 f3 f4 +9 0 2 6 +insert into t1 values (52,0,1,0),(53,0,1,0); +insert into t1 values (50,0,1,0),(51,0,1,0); +insert into t1 values (48,0,1,0),(49,0,1,0); +insert into t1 values (46,0,1,0),(47,0,1,0); +insert into t1 values (44,0,1,0),(45,0,1,0); +analyze table t1; +Table Op Msg_type Msg_text +test.t1 analyze status OK +explain select * from t1 +where (( f3 = 1 or f1 = 7 ) and f1 < 10) or +(f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t1 index_merge PRIMARY,f3,f4 f3,PRIMARY,f3 5,4,5 NULL 13 Using union(f3,PRIMARY,f3); Using where +select * from t1 +where (( f3 = 1 or f1 = 7 ) and f1 < 10) or +(f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +f1 f2 f3 f4 +9 0 2 6 +drop table t0,t1; +set optimizer_switch= @optimizer_switch_save; diff --git a/mysql-test/r/range_vs_index_merge.result b/mysql-test/r/range_vs_index_merge.result index 0acaed3..752554a 100644 --- a/mysql-test/r/range_vs_index_merge.result +++ b/mysql-test/r/range_vs_index_merge.result @@ -1653,7 +1653,7 @@ SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); id select_type table type possible_keys key key_len ref rows Extra -1 SIMPLE t1 ALL PRIMARY,f3,f4 NULL NULL NULL 2 Using where +1 SIMPLE t1 index_merge PRIMARY,f3,f4 f3,PRIMARY,f3 5,4,5 NULL 3 Using union(f3,PRIMARY,f3); Using where SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); diff --git a/mysql-test/t/index_merge_myisam.test b/mysql-test/t/index_merge_myisam.test index 82d0474..79aa544 100644 --- a/mysql-test/t/index_merge_myisam.test +++ b/mysql-test/t/index_merge_myisam.test @@ -243,3 +243,51 @@ DROP TABLE t1; set optimizer_switch= @optimizer_switch_save; +--echo # +--echo # MDEV-21932: ROR union with index_merge_sort_union=off +--echo # + +create table t0 (a int); +insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); +insert into t0 select a+10 from t0; +insert into t0 select a+20 from t0; +insert into t0 select a+40 from t0; +insert into t0 select a+80 from t0; +insert into t0 select a+160 from t0; +delete from t0 where a > 300; + +create table t1 ( + f1 int, f2 int, f3 int, f4 int, + primary key (f1), key (f3), key(f4) +) engine=myisam; +insert into t1 select a+100, a+100, a+100, a+100 from t0; +insert into t1 VALUES (9,0,2,6), (9930,0,0,NULL); +analyze table t1; + +set optimizer_switch='index_merge_sort_union=off'; +set optimizer_switch='index_merge_union=on'; + +let $q1= +select * from t1 + where (( f3 = 1 or f1 = 7 ) and f1 < 10) or + (f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +eval explain $q1; +eval $q1; + +insert into t1 values (52,0,1,0),(53,0,1,0); +insert into t1 values (50,0,1,0),(51,0,1,0); +insert into t1 values (48,0,1,0),(49,0,1,0); +insert into t1 values (46,0,1,0),(47,0,1,0); +insert into t1 values (44,0,1,0),(45,0,1,0); +analyze table t1; + +let $q2= +select * from t1 + where (( f3 = 1 or f1 = 7 ) and f1 < 10) or + (f3 between 2 and 2 and ( f3 = 1 or f4 < 7 )); +eval explain $q2; +eval $q2; + +drop table t0,t1; + +set optimizer_switch= @optimizer_switch_save; diff --git a/sql/opt_range.cc b/sql/opt_range.cc index ca6f500..70c1786 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -6802,6 +6802,13 @@ static TRP_RANGE *get_key_scans_params(PARAM *param, SEL_TREE *tree, update_tbl_stats, &mrr_flags, &buf_size, &cost); + if (!param->is_ror_scan && + !optimizer_flag(param->thd, OPTIMIZER_SWITCH_INDEX_MERGE_SORT_UNION)) + { + /* The scan is not a ROR-scan, just skip it */ + continue; + } + if (found_records != HA_POS_ERROR && tree->index_scans && (index_scan= (INDEX_SCAN_INFO *)alloc_root(param->mem_root, sizeof(INDEX_SCAN_INFO))))