- Address review feedback: change expression analyzer used to be a copy-paste
of ref analyzer. ref analyzer, besides doing ref analysis, also collected
info about keys which had sargable predicates. We didn't need that part here.
- Switch from uniform graph to bipartite graph with two kinds of nodes:
"values" (tables and fields) and "modules" (t.col=func(...) equalities,
multi-equalities, unique keys, inner sides of outer joins).
- Rename functions, classes, etc.
Address review feedback:
- Change from Wave-based approach (a-la const table detection) to
building and walking functional dependency graph.
- Change from piggy-backing on ref-access code and KEYUSE structures
to using our own expression analyzer.
sql/item.cc:
MWL#17: Table elimination
- Move from C-ish Field_processor_info to C++ ish and generic Field_enumerator
sql/item.h:
MWL#17: Table elimination
- Move from C-ish Field_processor_info to C++ ish and generic Field_enumerator
sql/sql_bitmap.h:
MWL#17: Table elimination
- Backport of Table_map_iterator from 6.0
- Last fixes
sql/item.cc:
MWL#17: Table elimination
- Don't make multiple calls of ::walk(check_column_usage_processor),
call once and cache the value
sql/item.h:
MWL#17: Table elimination
- s/KEYUSE::usable/KEYUSE::type/, more comments
sql/opt_table_elimination.cc:
MWL#17: Table elimination
- Don't make multiple calls of ::walk(check_column_usage_processor),
call once and cache the value
sql/sql_select.cc:
MWL#17: Table elimination
- s/KEYUSE::usable/KEYUSE::type/, more comments
sql/sql_select.h:
MWL#17: Table elimination
- s/KEYUSE::usable/KEYUSE::type/, more comments
sql/table.h:
MWL#17: Table elimination
- Better comments
