AggregatingMergeTree

import {   OlapTable,   ClickHouseEngines,   SimpleAggregated,  Aggregated,  DateTime} from "@514labs/moose-lib"; interface DailyStats {  date: DateTime;  user_id: string;  // SimpleAggregateFunction(sum, UInt64)  total_views: number & SimpleAggregated<"sum", number>;  // SimpleAggregateFunction(max, Float64)  max_score: number & SimpleAggregated<"max", number>;  // SimpleAggregateFunction(anyLast, DateTime)  last_activity: DateTime & SimpleAggregated<"anyLast", DateTime>;} const dailyStats = new OlapTable<DailyStats>("daily_stats", {  engine: ClickHouseEngines.AggregatingMergeTree,  orderByFields: ["date", "user_id"]}); interface MetricsById {  id: string;  /**   * AggregateFunction(avg, Float64)   * Stores the result of avgState(rating) and is merged with avgMerge(...)   */  avg_rating: number & Aggregated<"avg", [number]>;  /**   * AggregateFunction(uniqExact, String)   * Stores the result of uniqExactState(user_id) and is merged with uniqExactMerge(...)   */  daily_uniques: number & Aggregated<"uniqExact", [string]>;} const metricsById = new OlapTable<MetricsById>("metrics_by_id", {  engine: ClickHouseEngines.AggregatingMergeTree,  orderByFields: ["id"],});

import {   OlapTable,   MaterializedView,  ClickHouseEngines,  UInt64,  SimpleAggregated,  DateTime,  sql} from "@514labs/moose-lib"; // Source: raw eventsinterface PageView {  timestamp: DateTime;  user_id: string;  page: string;  duration_ms: number;} const pageViews = new OlapTable<PageView>("page_views", {  orderByFields: ["timestamp", "user_id"],}); // Target: daily aggregatesinterface DailyPageStats {  date: DateTime;  user_id: string;  view_count: UInt64 & SimpleAggregated<"sum", UInt64>;  total_duration: number & SimpleAggregated<"sum", number>;  max_duration: number & SimpleAggregated<"max", number>;} const targetTable = new OlapTable<DailyPageStats>("daily_page_stats", {  engine: ClickHouseEngines.AggregatingMergeTree,  orderByFields: ["date", "user_id"],}); const mv = new MaterializedView<DailyPageStats>({  materializedViewName: "mv_daily_page_stats",  selectTables: [pageViews],  targetTable: targetTable,  selectStatement: sql`    SELECT      toStartOfDay(${pageViews.columns.timestamp}) AS date,      ${pageViews.columns.user_id}                AS user_id,      count()                                     AS view_count,      sum(${pageViews.columns.duration_ms})       AS total_duration,      max(${pageViews.columns.duration_ms})       AS max_duration    FROM ${pageViews}    GROUP BY date, user_id  `,});