fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/PruneEmptyPartition.java

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package org.apache.doris.nereids.rules.rewrite;

import org.apache.doris.catalog.OlapTable;
import org.apache.doris.nereids.rules.Rule;
import org.apache.doris.nereids.rules.RuleType;
import org.apache.doris.nereids.trees.plans.logical.LogicalOlapScan;

import java.util.stream.Collectors;

/**
 * Used to prune empty partition.
 */
public class PruneEmptyPartition extends OneRewriteRuleFactory {

    @Override
    public Rule build() {
        return logicalOlapScan().thenApply(ctx -> {
            LogicalOlapScan scan = ctx.root;
            OlapTable table = scan.getTable();
            return scan.withSelectedPartitionIds(scan.getSelectedPartitionIds().stream()
                    .filter(partitionId -> table.getPartition(partitionId).hasData())
                    .collect(Collectors.toList()));
        }).toRule(RuleType.PRUNE_EMPTY_PARTITION);
    }
}