[IGNITE-18635] Sql. Extra comparison in case of index scan and simple predicate.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0-beta1
• Component/s: sql
• Labels: calcite3-required ignite-3
• Epic Link: AI3 Performance
• Assignee: Unassigned
• Reporter: Evgeny Stanilovsky
• Created: 25/Jan/23 12:32
• Updated: 13/Jun/23 13:33

Description

IndexScanNode contains :

IgniteIndex schemaIndex
RangeIterable<RowT> rangeConditions
Predicate<RowT> filters

Seems that for some simple predicates no additional filters comparison is needed.
For example :

create table t (a int);
create index a_idx on t (a);
select a from t where a = 1;

If correct index scan is used here, no need in additional comparisons:

                    if (filters != null && !filters.test(row)) {
                        continue;
                    }

Seems for more complex cases: sort indexes and range this optimization still applicable:

create table t (a int);
create index a_idx on t (a);
select a from t where a > 5 and a < 10;