#At lp:maria based on revid:igor@askmonty.org-20091029184958-1b1iyhu09sihxc6o 2748 Igor Babaev 2009-10-29 Fixed a bug in the code of the patch for WL#24 that manifested itself when running the pbxt.group_min_max test leading to wrong result sets and execution plans for many test cases. When evaluating the index merge scans the code ignored the following: if an index merge contains a range tree, such that none of its SEL_ARG trees represents index ranges, then the index merge must be discarded as not usable for any index merge retrieval. modified: sql/opt_range.cc === modified file 'sql/opt_range.cc' --- a/sql/opt_range.cc 2009-10-29 18:49:58 +0000 +++ b/sql/opt_range.cc 2009-10-30 00:36:35 +0000 @@ -265,7 +265,7 @@ public: The ordinal number the least significant component encountered the ranges of the SEL_ARG tree (the first component has number 1) */ - uint max_part_no; + uint16 max_part_no; /* Number of children of this element in the RB-tree, plus 1 for this element itself. @@ -2195,9 +2195,10 @@ SEL_ARG::SEL_ARG(Field *f,const uchar *m :min_flag(0), max_flag(0), maybe_flag(0), maybe_null(f->real_maybe_null()), elements(1), use_count(1), field(f), min_value((uchar*) min_value_arg), max_value((uchar*) max_value_arg), next(0),prev(0), - next_key_part(0), color(BLACK), type(KEY_RANGE), max_part_no(1) + next_key_part(0), color(BLACK), type(KEY_RANGE) { left=right= &null_element; + max_part_no= 1; } SEL_ARG::SEL_ARG(Field *field_,uint8 part_, @@ -4247,18 +4248,16 @@ TABLE_READ_PLAN *get_best_disjunct_quick /* In every tree of imerge remove SEL_ARG trees that do not make ranges. - Remove a tree from imerge if no SEL_ARG trees remain in it. + If after this removal some SEL_ARG tree becomes empty discard imerge. */ - SEL_TREE **new_trees_next= imerge->trees; - for (ptree= new_trees_next; ptree != imerge->trees_next; ptree++) + for (ptree= imerge->trees; ptree != imerge->trees_next; ptree++) { if (remove_nonrange_trees(param, *ptree)) - continue; - if (ptree > new_trees_next) - *new_trees_next= *ptree; - new_trees_next++; + { + imerge->trees_next= imerge->trees; + break; + } } - imerge->trees_next= new_trees_next; uint n_child_scans= imerge->trees_next - imerge->trees; @@ -7111,7 +7110,9 @@ bool sel_trees_must_be_ored(RANGE_OPT_PA can be built. Such SEL_ARG trees should be removed from the range part before different range scans are evaluated. Such SEL_ARG trees also should be removed from all range trees of each index merge before different - possible index merge plans are evaluated. + possible index merge plans are evaluated. If after this removal one + of the range trees in the index merge becomes empty the whole index merge + must be discarded. RETURN 0 Ok, some suitable trees left