public void analyzeTable()

in src/spark-project/engine-spark/src/main/java/org/apache/kylin/engine/spark/job/TableAnalyzeJob.java [77:154]
72 lines of code
12 McCabe index (conditional complexity)

    public void analyzeTable(TableDesc tableDesc, String project, int rowCount, SparkSession ss) {

        long start = System.currentTimeMillis();
        Row[] row = new TableAnalyzeExec(tableDesc, project, rowCount, ss, jobId).analyzeTable();
        logger.info("sampling rows from table {} takes {}s", tableDesc.getIdentity(),
                (System.currentTimeMillis() - start) / 1000);

        val tableMetadataManager = NTableMetadataManager.getInstance(KylinConfig.getInstanceFromEnv(), project);
        var tableExtDesc = tableMetadataManager.getOrCreateTableExt(tableDesc);
        final long count_star = Long.parseLong(row[0].get(0).toString());
        final List<TableExtDesc.ColumnStats> columnStatsList = new ArrayList<>(tableDesc.getColumnCount());
        for (int colIdx = 0; colIdx < tableDesc.getColumnCount(); colIdx++) {
            final ColumnDesc columnDesc = tableDesc.getColumns()[colIdx];
            if (columnDesc.isComputedColumn()) {
                continue;
            }
            TableExtDesc.ColumnStats colStats = tableExtDesc.getColumnStatsByName(columnDesc.getName());
            if (colStats == null) {
                colStats = new TableExtDesc.ColumnStats();
                colStats.setColumnName(columnDesc.getName());
            }
            int metricLen = TABLE_STATS_METRICS.size();
            for (int i = 0; i < metricLen; i++) {
                String value = row[0].get(i + 1 + metricLen * colIdx) == null ? null
                        : row[0].get(i + 1 + metricLen * colIdx).toString();

                switch (TABLE_STATS_METRICS.get(i)) {
                case "COUNT":
                    colStats.setNullCount(count_star - Long.parseLong(value));
                    break;
                case "MAX":
                    colStats.setMaxValue(value);
                    break;
                case "MIN":
                    colStats.setMinValue(value);
                    break;
                case "COUNT_DISTINCT":
                    colStats.setCardinality(Long.parseLong(value));
                    break;
                default:
                    throw new IllegalArgumentException(
                            "not support this metric" + TABLE_STATS_METRICS.get(i) + "in table Sampling");
                }
            }
            columnStatsList.add(colStats);
        }

        List<String[]> sampleData = Lists.newArrayList();
        IntStream.range(1, row.length).forEach(i -> {
            String[] data = new String[row[i].length()];
            IntStream.range(0, row[i].length()).forEach(j -> {
                final Object obj = row[i].get(j);
                if (obj == null) {
                    data[j] = null;
                } else if (obj instanceof Timestamp) {
                    data[j] = DateFormat.castTimestampToString(((Timestamp) obj).getTime());
                } else {
                    data[j] = obj.toString();
                }
            });
            sampleData.add(data);
        });

        UnitOfWork.doInTransactionWithRetry(() -> {
            val tableMetadataManagerForUpdate = NTableMetadataManager.getInstance(KylinConfig.getInstanceFromEnv(),
                    project);
            var tableExt = tableMetadataManagerForUpdate.getOrCreateTableExt(tableDesc);
            tableExt = tableMetadataManagerForUpdate.copyForWrite(tableExt);
            tableExt.setTotalRows(count_star);
            tableExt.setColumnStats(columnStatsList);
            tableExt.setSampleRows(sampleData);
            tableExt.setJodID(jobId);
            tableMetadataManagerForUpdate.saveTableExt(tableExt);

            return null;
        }, project);
        logger.info("Table {} analysis finished, update table ext desc done.", tableDesc.getName());
    }