[IGNITE-23244] Sql. Provide information about PK to planner through statistics

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: sql
• Labels: ignite-3
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Unassigned
• Reporter: Iurii Gerzhedovich
• Created: 20/Sep/24 12:28
• Updated: 11/Oct/24 11:51

Description

IgniteStatistic doesn't implement two methods from the base Statistic interface:

boolean isKey(ImmutableBitSet columns)

List<ImmutableBitSet> getKeys()

We can provide this information to start using it during the planning phase.
Need just provide information about PK columns to the class and implementation of the methods can be like a:

@Override
public boolean isKey(ImmutableBitSet columns) {
    return columns.contains(pkColumns.get(0));
}

@Override
public List<ImmutableBitSet> getKeys() {
    return pkColumns;
} 

Right now the methods used in RelMdColumnUniqueness and RelMdUniqueKeys