Class MergeStmt

fe/src/main/java/org/apache/impala/analysis/MergeStmt.java:42–202

Representation of the MERGE statement. The MERGE statement has one target table, and a source expression that is joined with an ON clause. The statement consists of WHEN MATCHED / WHEN NOT MATCHED clauses referenced as merge cases, the evaluation of these cases are following the order of their defin

 * of the target table by conditions defined by merge cases.
 */
public class MergeStmt extends DmlStatementBase {
  private static final int MERGE_CASE_LIMIT = 1000;
  private TableRef targetTableRef_;
  private TableRef sourceTableRef_;
  private final List<MergeCase> cases_;
  private final Expr onClause_;
  private MergeImpl impl_;

  public MergeStmt(TableRef target, TableRef source, Expr onClause,
      List<MergeCase> cases) {
    targetTableRef_ = target;
    sourceTableRef_ = source;
    onClause_ = onClause;
    cases_ = cases;
  }

  @Override
  public void analyze(Analyzer analyzer) throws AnalysisException {
    if (isAnalyzed()) return;
    super.analyze(analyzer);
    if (targetTableRef_ instanceof InlineViewRef) {
      throw new AnalysisException(
          String.format("Cannot modify view: %s", targetTableRef_.toSql()));
    }

    if (cases_.size() > MERGE_CASE_LIMIT) {
      String sql = toSql();
      String sqlSubstr = sql.substring(0, Math.min(80, sql.length()));
      throw new AnalysisException(String.format("Exceeded the maximum number of cases " +
          "(%s).\nStatement has %s cases:\n%s...",
          MERGE_CASE_LIMIT, cases_.size(), sqlSubstr));
    }

    sourceTableRef_ = analyzer.resolveTableRef(sourceTableRef_);
    targetTableRef_ = analyzer.resolveTableRef(targetTableRef_);

    table_ = targetTableRef_.getTable();

    if (impl_ == null) {
      if (table_ instanceof FeIcebergTable) {
        impl_ = new IcebergMergeImpl(this, targetTableRef_, sourceTableRef_, onClause_);
        setMaxTableSinks(analyzer_.getQueryOptions().getMax_fs_writers());
      } else {
        throw new AnalysisException(String.format(
            "Target table must be an Iceberg table: %s", table_.getFullName()));
      }
    }

    impl_.analyze(analyzer);

    for (MergeCase mergeCase : getCases()) {
      mergeCase.setParent(this);
      mergeCase.analyze(analyzer);
    }
  }

  @Override
  public void collectTableRefs(List<TableRef> tblRefs) {