Code review comment: The most risky bug in this code is: Modifying the column definitions to set `columnDef.setAllowNull(false)` might affect columns that should allow null values outside of the list partitioning context.  You can modify the code like this: ``` @@ -192,7 +193,11 @@ public static void analyze(CreateTableAsSelectStmt createTableAsSelectStmt, Conn          for (ColumnDef columnDef : columnDefs) {              for (String partitionColName : ((ListPartitionDesc) partitionDesc).getPartitionColNames()) {                  if (columnDef.getName().equalsIgnoreCase(partitionColName)) { -                    columnDef.setAllowNull(false); +                    if (columnDef.isKey()) { +                        columnDef.setAllowNull(false); +                    } else { +                        throw new ParsingException("List partition column must be a key column and not allow nulls", rangePartitionDesc.getPos()); +                    }                  }              }          } ``` This change ensures that only the necessary columns that are part of the primary key or some sort of key (which typically do not allow null values by their nature) are affected. It also adds an exception to catch cases where a list partition column is mistakenly set as allowing nulls but is not defined as a key column. Adjust the specifics according to your actual schema requirements and how the column key status check should be done (`columnDef.isKey()` is just a placeholder for whatever the actual method call should be).   Make sure to handle exceptions properly and provide adequate error messages to guide the user.

Code under review:
public static void analyze(CreateTableAsSelectStmt createTableAsSelectStmt, ConnectContext session) {
        List<String> columnNames = createTableAsSelectStmt.getColumnNames();
        QueryStatement queryStatement = createTableAsSelectStmt.getQueryStatement();
        CreateTableStmt createTableStmt = createTableAsSelectStmt.getCreateTableStmt();

        if (createTableStmt.isExternal()) {
            throw new SemanticException("CTAS does not support create external table");
        }

        Analyzer.analyze(queryStatement, session);

        
        Map<Pair<String, Pair<String, String>>, Table> columnNameToTable = Maps.newHashMap();
        Map<TableName, Table> tables = AnalyzerUtils.collectAllTableWithAlias(queryStatement);
        Map<String, Table> tableRefToTable = new HashMap<>();
        for (Map.Entry<TableName, Table> t : tables.entrySet()) {
            tableRefToTable.put(t.getKey().getTbl(), t.getValue());
        }

        List<Field> allFields = queryStatement.getQueryRelation().getRelationFields().getAllFields();
        List<String> finalColumnNames = Lists.newArrayList();

        if (columnNames != null) {
            if (columnNames.size() != allFields.size()) {
                throw new SemanticException("Number of select columns [%d] don't equal query statement's columns [%d]",
                        columnNames.size(), allFields.size());
            }
            finalColumnNames.addAll(columnNames);
        } else {
            for (Field allField : allFields) {
                finalColumnNames.add(allField.getName());
            }
        }

        boolean isPKTable = false;
        KeysDesc keysDesc = createTableStmt.getKeysDesc();
        if (keysDesc != null) {
            KeysType keysType = keysDesc.getKeysType();
            if (keysType == KeysType.PRIMARY_KEYS) {
                isPKTable = true;
            } else if (keysType != KeysType.DUP_KEYS) {
                throw new SemanticException("CTAS does not support %s table", keysDesc.getKeysType().toString());
            }
        }

        for (int i = 0; i < allFields.size(); i++) {
            Type type = AnalyzerUtils.transformTableColumnType(allFields.get(i).getType());
            Expr originExpression = allFields.get(i).getOriginExpression();
            ColumnDef columnDef = new ColumnDef(finalColumnNames.get(i), new TypeDef(type), false,
                    null, originExpression.isNullable(), ColumnDef.DefaultValueDef.NOT_SET, "");
            if (isPKTable && keysDesc.containsCol(finalColumnNames.get(i))) {
                columnDef.setAllowNull(false);
            }
            createTableStmt.addColumnDef(columnDef);
            if (originExpression instanceof SlotRef) {
                SlotRef slotRef = (SlotRef) originExpression;
                
                if (slotRef.getTblNameWithoutAnalyzed() == null) {
                    continue;
                }
                String tableName = slotRef.getTblNameWithoutAnalyzed().getTbl();
                Table table = tableRefToTable.get(tableName);
                if (!(table instanceof OlapTable)) {
                    continue;
                }
                columnNameToTable.put(new Pair<>(tableName,
                        new Pair<>(slotRef.getColumnName(), allFields.get(i).getName())), table);
            }
        }

        
        int defaultReplicationNum = RunMode.defaultReplicationNum();

        Map<String, String> stmtProperties = createTableStmt.getProperties();
        if (null == stmtProperties) {
            Map<String, String> properties = Maps.newHashMap();
            properties.put("replication_num", String.valueOf(defaultReplicationNum));
            createTableStmt.setProperties(properties);
        } else if (!stmtProperties.containsKey("replication_num")) {
            stmtProperties.put("replication_num", String.valueOf(defaultReplicationNum));
        }

        if (null == createTableStmt.getDistributionDesc()) {
            if ((createTableStmt.getKeysDesc() != null && createTableStmt.getKeysDesc().getKeysType() != KeysType.DUP_KEYS)
                    || createTableStmt.getProperties().containsKey("colocate_with")) {
                
                
                
                String defaultColumnName = finalColumnNames.get(0);
                double candidateDistinctCountCount = 1.0;
                StatisticStorage currentStatisticStorage = GlobalStateMgr.getCurrentStatisticStorage();

                for (Map.Entry<Pair<String, Pair<String, String>>, Table> columnEntry : columnNameToTable.entrySet()) {
                    Pair<String, String> columnName = columnEntry.getKey().second;
                    ColumnStatistic columnStatistic = currentStatisticStorage.getColumnStatistic(
                            columnEntry.getValue(), columnName.first);
                    double curDistinctValuesCount = columnStatistic.getDistinctValuesCount();
                    if (curDistinctValuesCount > candidateDistinctCountCount) {
                        defaultColumnName = columnName.second;
                        candidateDistinctCountCount = curDistinctValuesCount;
                    }
                }

                DistributionDesc distributionDesc =
                        new HashDistributionDesc(0, Lists.newArrayList(defaultColumnName));
                createTableStmt.setDistributionDesc(distributionDesc);
            } else {
                
                DistributionDesc distributionDesc = new RandomDistributionDesc();
                createTableStmt.setDistributionDesc(distributionDesc);
            }
        }

        PartitionDesc partitionDesc = createTableStmt.getPartitionDesc();
        List<ColumnDef> columnDefs = createTableStmt.getColumnDefs();

        if (partitionDesc instanceof ExpressionPartitionDesc) {
            ExpressionPartitionDesc expressionPartitionDesc = (ExpressionPartitionDesc) partitionDesc;
            FunctionCallExpr functionCallExpr = (FunctionCallExpr) expressionPartitionDesc.getExpr();
            AnalyzerUtils.checkAndExtractPartitionCol(functionCallExpr, columnDefs);
            String currentGranularity = null;
            RangePartitionDesc rangePartitionDesc = expressionPartitionDesc.getRangePartitionDesc();
            if (!rangePartitionDesc.getSingleRangePartitionDescs().isEmpty()) {
                throw new ParsingException("Expression partition table creation only supports " +
                        "batch create partition syntax", rangePartitionDesc.getPos());
            }
            List<MultiRangePartitionDesc> multiRangePartitionDescs = rangePartitionDesc.getMultiRangePartitionDescs();
            for (MultiRangePartitionDesc multiRangePartitionDesc : multiRangePartitionDescs) {
                String descGranularity = multiRangePartitionDesc.getTimeUnit().toLowerCase();
                if (currentGranularity == null) {
                    currentGranularity = descGranularity;
                } else if (!currentGranularity.equals(descGranularity)) {
                    throw new ParsingException("The partition granularity of expression partition table " +
                            "batch creation in advance should be consistent", rangePartitionDesc.getPos());
                }
            }
            AnalyzerUtils.checkAutoPartitionTableLimit(functionCallExpr, currentGranularity);
            rangePartitionDesc.setAutoPartitionTable(true);
        } else if (partitionDesc instanceof ListPartitionDesc) {
            for (ColumnDef columnDef : columnDefs) {
                for (String partitionColName : ((ListPartitionDesc) partitionDesc).getPartitionColNames()) {
                    if (columnDef.getName().equalsIgnoreCase(partitionColName)) {
                        columnDef.setAllowNull(false);
                    }
                }
            }
        }

        Analyzer.analyze(createTableStmt, session);

        InsertStmt insertStmt = createTableAsSelectStmt.getInsertStmt();
        insertStmt.setQueryStatement(queryStatement);
    }

Line commented on: Analyzer.analyze(createTableStmt, session);

Revised code:
public static void analyze(CreateTableAsSelectStmt createTableAsSelectStmt, ConnectContext session) {
        List<String> columnNames = createTableAsSelectStmt.getColumnNames();
        QueryStatement queryStatement = createTableAsSelectStmt.getQueryStatement();
        CreateTableStmt createTableStmt = createTableAsSelectStmt.getCreateTableStmt();

        if (createTableStmt.isExternal()) {
            throw new SemanticException("CTAS does not support create external table");
        }

        Analyzer.analyze(queryStatement, session);

        
        Map<Pair<String, Pair<String, String>>, Table> columnNameToTable = Maps.newHashMap();
        Map<TableName, Table> tables = AnalyzerUtils.collectAllTableWithAlias(queryStatement);
        Map<String, Table> tableRefToTable = new HashMap<>();
        for (Map.Entry<TableName, Table> t : tables.entrySet()) {
            tableRefToTable.put(t.getKey().getTbl(), t.getValue());
        }

        List<Field> allFields = queryStatement.getQueryRelation().getRelationFields().getAllFields();
        List<String> finalColumnNames = Lists.newArrayList();

        if (columnNames != null) {
            if (columnNames.size() != allFields.size()) {
                throw new SemanticException("Number of select columns [%d] don't equal query statement's columns [%d]",
                        columnNames.size(), allFields.size());
            }
            finalColumnNames.addAll(columnNames);
        } else {
            for (Field allField : allFields) {
                finalColumnNames.add(allField.getName());
            }
        }

        boolean isPKTable = false;
        KeysDesc keysDesc = createTableStmt.getKeysDesc();
        if (keysDesc != null) {
            KeysType keysType = keysDesc.getKeysType();
            if (keysType == KeysType.PRIMARY_KEYS) {
                isPKTable = true;
            } else if (keysType != KeysType.DUP_KEYS) {
                throw new SemanticException("CTAS does not support %s table", keysDesc.getKeysType().toString());
            }
        }

        for (int i = 0; i < allFields.size(); i++) {
            Type type = AnalyzerUtils.transformTableColumnType(allFields.get(i).getType());
            Expr originExpression = allFields.get(i).getOriginExpression();
            ColumnDef columnDef = new ColumnDef(finalColumnNames.get(i), new TypeDef(type), false,
                    null, originExpression.isNullable(), ColumnDef.DefaultValueDef.NOT_SET, "");
            if (isPKTable && keysDesc.containsCol(finalColumnNames.get(i))) {
                columnDef.setAllowNull(false);
            }
            createTableStmt.addColumnDef(columnDef);
            if (originExpression instanceof SlotRef) {
                SlotRef slotRef = (SlotRef) originExpression;
                
                if (slotRef.getTblNameWithoutAnalyzed() == null) {
                    continue;
                }
                String tableName = slotRef.getTblNameWithoutAnalyzed().getTbl();
                Table table = tableRefToTable.get(tableName);
                if (!(table instanceof OlapTable)) {
                    continue;
                }
                columnNameToTable.put(new Pair<>(tableName,
                        new Pair<>(slotRef.getColumnName(), allFields.get(i).getName())), table);
            }
        }

        
        int defaultReplicationNum = RunMode.defaultReplicationNum();

        Map<String, String> stmtProperties = createTableStmt.getProperties();
        if (null == stmtProperties) {
            Map<String, String> properties = Maps.newHashMap();
            properties.put("replication_num", String.valueOf(defaultReplicationNum));
            createTableStmt.setProperties(properties);
        } else if (!stmtProperties.containsKey("replication_num")) {
            stmtProperties.put("replication_num", String.valueOf(defaultReplicationNum));
        }

        if (null == createTableStmt.getDistributionDesc()) {
            if ((createTableStmt.getKeysDesc() != null && createTableStmt.getKeysDesc().getKeysType() != KeysType.DUP_KEYS)
                    || createTableStmt.getProperties().containsKey("colocate_with")) {
                
                
                
                String defaultColumnName = finalColumnNames.get(0);
                double candidateDistinctCountCount = 1.0;
                StatisticStorage currentStatisticStorage = GlobalStateMgr.getCurrentStatisticStorage();

                for (Map.Entry<Pair<String, Pair<String, String>>, Table> columnEntry : columnNameToTable.entrySet()) {
                    Pair<String, String> columnName = columnEntry.getKey().second;
                    ColumnStatistic columnStatistic = currentStatisticStorage.getColumnStatistic(
                            columnEntry.getValue(), columnName.first);
                    double curDistinctValuesCount = columnStatistic.getDistinctValuesCount();
                    if (curDistinctValuesCount > candidateDistinctCountCount) {
                        defaultColumnName = columnName.second;
                        candidateDistinctCountCount = curDistinctValuesCount;
                    }
                }

                DistributionDesc distributionDesc =
                        new HashDistributionDesc(0, Lists.newArrayList(defaultColumnName));
                createTableStmt.setDistributionDesc(distributionDesc);
            } else {
                
                DistributionDesc distributionDesc = new RandomDistributionDesc();
                createTableStmt.setDistributionDesc(distributionDesc);
            }
        }

        PartitionDesc partitionDesc = createTableStmt.getPartitionDesc();
        List<ColumnDef> columnDefs = createTableStmt.getColumnDefs();

        if (partitionDesc instanceof ExpressionPartitionDesc) {
            ExpressionPartitionDesc expressionPartitionDesc = (ExpressionPartitionDesc) partitionDesc;
            FunctionCallExpr functionCallExpr = (FunctionCallExpr) expressionPartitionDesc.getExpr();
            AnalyzerUtils.checkAndExtractPartitionCol(functionCallExpr, columnDefs);
            String currentGranularity = null;
            RangePartitionDesc rangePartitionDesc = expressionPartitionDesc.getRangePartitionDesc();
            if (!rangePartitionDesc.getSingleRangePartitionDescs().isEmpty()) {
                throw new ParsingException("Automatic partition table creation only supports " +
                        "batch create partition syntax", rangePartitionDesc.getPos());
            }
            List<MultiRangePartitionDesc> multiRangePartitionDescs = rangePartitionDesc.getMultiRangePartitionDescs();
            for (MultiRangePartitionDesc multiRangePartitionDesc : multiRangePartitionDescs) {
                String descGranularity = multiRangePartitionDesc.getTimeUnit().toLowerCase();
                if (currentGranularity == null) {
                    currentGranularity = descGranularity;
                } else if (!currentGranularity.equals(descGranularity)) {
                    throw new ParsingException("The partition granularity of automatic partition table " +
                            "batch creation in advance should be consistent", rangePartitionDesc.getPos());
                }
            }
            AnalyzerUtils.checkAutoPartitionTableLimit(functionCallExpr, currentGranularity);
            rangePartitionDesc.setAutoPartitionTable(true);
        } else if (partitionDesc instanceof ListPartitionDesc) {
            for (ColumnDef columnDef : columnDefs) {
                for (String partitionColName : ((ListPartitionDesc) partitionDesc).getPartitionColNames()) {
                    if (columnDef.getName().equalsIgnoreCase(partitionColName)) {
                        columnDef.setAllowNull(false);
                    }
                }
            }
        }

        Analyzer.analyze(createTableStmt, session);

        InsertStmt insertStmt = createTableAsSelectStmt.getInsertStmt();
        insertStmt.setQueryStatement(queryStatement);
    }