refactor(base): single duckdb instance with per-base attached databases

apps/server/src/core/base/query-cache/base-query-cache.service.ts

@@ -27,6 +27,7 @@ import {
 import { QueryCacheConfigProvider } from './query-cache.config';
 import { CollectionLoader } from './collection-loader';
 import { buildDuckDbListQuery } from './duckdb-query-builder';
+import { DuckDbRuntime } from './duckdb-runtime';
 import { BasePropertyType } from '../base.schemas';
 import {
   ChangeEnvelope,
@@ -55,6 +56,7 @@ export class BaseQueryCacheService
     private readonly configProvider: QueryCacheConfigProvider,
     private readonly baseRepo: BaseRepo,
     private readonly collectionLoader: CollectionLoader,
+    private readonly runtime: DuckDbRuntime,
     @Optional() private readonly redisService: RedisService | null = null,
     @Optional() private readonly env: EnvironmentService | null = null,
   ) {}
@@ -62,8 +64,14 @@ export class BaseQueryCacheService
   async onApplicationBootstrap(): Promise<void> {
     const { enabled, warmTopN } = this.configProvider.config;
     if (!enabled) return;
+    if (!this.runtime.isReady()) {
+      this.logger.warn('runtime not ready; skipping warm-up');
+      return;
+    }
+
     const redis = this.tryGetRedisClient();
     if (!redis) return;
+
     try {
       const ids = await redis.zrevrange(
         'base-query-cache:recent',
@@ -89,41 +97,10 @@ export class BaseQueryCacheService
     }
   }
 
-  private tryGetRedisClient(): Redis | null {
-    if (!this.redisService) return null;
-    try {
-      return this.redisService.getOrNil();
-    } catch {
-      return null;
-    }
-  }
-
-  private recordAccess(baseId: string): void {
-    if (!this.configProvider.config.enabled) return;
-    const redis = this.tryGetRedisClient();
-    if (!redis) return;
-    const nowMs = Date.now();
-    const maxKeep = this.configProvider.config.maxCollections * 10;
-    void (async () => {
-      try {
-        await redis.zadd('base-query-cache:recent', nowMs, baseId);
-        await redis.zremrangebyrank(
-          'base-query-cache:recent',
-          0,
-          -(maxKeep + 1),
-        );
-      } catch (err) {
-        this.logger.debug(
-          `recordAccess failed for ${baseId}: ${(err as Error).message}`,
-        );
-      }
-    })();
-  }
-
   async onModuleDestroy(): Promise<void> {
-    for (const [, collection] of this.collections) {
+    // The runtime owns the instance/connection lifecycle; we just clear
-      this.closeCollection(collection);
+    // our metadata. DETACH is a no-op during shutdown because the instance
-    }
+    // is closing anyway.
     this.collections.clear();
   }
 
@@ -133,6 +110,7 @@ export class BaseQueryCacheService
     opts: CacheListOpts,
   ): Promise<CursorPaginationResult<BaseRow>> {
     const debug = this.env?.getBaseQueryCacheDebug() ?? false;
+    const trace = this.env?.getBaseQueryCacheTrace?.() ?? false;
     const tStart = debug ? Date.now() : 0;
 
     const tEnsure = debug ? Date.now() : 0;
@@ -143,9 +121,7 @@ export class BaseQueryCacheService
       opts.sorts && opts.sorts.length > 0
         ? buildSorts(opts.sorts, opts.schema)
         : [];
-
     const cursor = makeCursor(sortBuilds, CURSOR_TAIL_KEYS);
-
     const sortFieldKeys = sortBuilds.map((s) => s.key);
     const allFieldKeys = [...sortFieldKeys, 'position', 'id'];
 
@@ -164,42 +140,45 @@ export class BaseQueryCacheService
         limit: opts.pagination.limit,
         afterKeys: afterKeys as any,
       },
+      schema: collection.schema,
     });
 
-    if (this.env?.getBaseQueryCacheTrace?.() ?? false) {
+    if (trace) {
       console.log(
         '[cache-trace]',
         JSON.stringify({
           phase: 'query.sql',
           baseId: baseId.slice(0, 8),
+          schema: collection.schema,
           sql,
           params,
         }),
       );
     }
 
-    const prepared = await collection.connection.prepare(sql);
-    for (let i = 0; i < params.length; i++) {
-      const p = params[i];
-      const oneBased = i + 1;
-      if (p === null || p === undefined) {
-        prepared.bindNull(oneBased);
-      } else if (typeof p === 'string') {
-        prepared.bindVarchar(oneBased, p);
-      } else if (typeof p === 'number') {
-        prepared.bindDouble(oneBased, p);
-      } else if (typeof p === 'boolean') {
-        prepared.bindBoolean(oneBased, p);
-      } else if (p instanceof Date) {
-        prepared.bindVarchar(oneBased, p.toISOString());
-      } else {
-        prepared.bindVarchar(oneBased, JSON.stringify(p));
-      }
-    }
-
     const tExec = debug ? Date.now() : 0;
-    const reader = await prepared.runAndReadAll();
+    const duckRows = await this.runtime.withReader(async (conn) => {
-    const duckRows = reader.getRowObjectsJS();
+      const prepared = await conn.prepare(sql);
+      for (let i = 0; i < params.length; i++) {
+        const p = params[i];
+        const oneBased = i + 1;
+        if (p === null || p === undefined) {
+          prepared.bindNull(oneBased);
+        } else if (typeof p === 'string') {
+          prepared.bindVarchar(oneBased, p);
+        } else if (typeof p === 'number') {
+          prepared.bindDouble(oneBased, p);
+        } else if (typeof p === 'boolean') {
+          prepared.bindBoolean(oneBased, p);
+        } else if (p instanceof Date) {
+          prepared.bindVarchar(oneBased, p.toISOString());
+        } else {
+          prepared.bindVarchar(oneBased, JSON.stringify(p));
+        }
+      }
+      const reader = await prepared.runAndReadAll();
+      return reader.getRowObjectsJS();
+    });
     const execMs = debug ? Date.now() - tExec : 0;
 
     const hasNextPage = duckRows.length > opts.pagination.limit;
@@ -231,12 +210,9 @@ export class BaseQueryCacheService
 
     const endRow = duckRows[duckRows.length - 1];
     const startRow = duckRows[0];
-
     const encodeFromRow = (raw: Record<string, unknown>): string => {
       const entries: Array<[string, unknown]> = [];
-      for (const sb of sortBuilds) {
+      for (const sb of sortBuilds) entries.push([sb.key, raw[sb.key]]);
-        entries.push([sb.key, raw[sb.key]]);
-      }
       entries.push(['position', raw.position]);
       entries.push(['id', raw.id]);
       return cursor.encodeCursor(entries);
@@ -276,13 +252,10 @@ export class BaseQueryCacheService
   async invalidate(baseId: string): Promise<void> {
     const collection = this.collections.get(baseId);
     if (!collection) return;
-    this.closeCollection(collection);
+    await this.runtime.detachBase(collection.schema);
     this.collections.delete(baseId);
   }
 
-  // Test-only introspection of the resident cache. Used by the LRU eviction
-  // integration spec to assert which collections are currently loaded without
-  // reaching into the private `collections` map.
   isResident(baseId: string): boolean {
     return this.collections.has(baseId);
   }
@@ -291,48 +264,38 @@ export class BaseQueryCacheService
     return this.collections.size;
   }
 
-  // Production-facing fast path for the router: returns the resident
-  // collection without triggering a load. Used to avoid a per-request
-  // Postgres COUNT when the cached rowCount already answers the question.
   peek(baseId: string): LoadedCollection | undefined {
     return this.collections.get(baseId);
   }
 
-  // Returns the memory footprint of every currently resident collection.
   residencySnapshot(): Array<{
     baseId: string;
+    schema: string;
     rows: number;
-    heapMb: number;
+    approxMb: number;
-    spilledMb: number;
   }> {
     const out: Array<{
       baseId: string;
+      schema: string;
       rows: number;
-      heapMb: number;
+      approxMb: number;
-      spilledMb: number;
     }> = [];
     for (const [baseId, c] of this.collections) {
       out.push({
         baseId,
+        schema: c.schema,
         rows: c.rowCount,
-        heapMb: +(c.heapBytes / (1024 * 1024)).toFixed(1),
+        approxMb: +(c.approxBytes / (1024 * 1024)).toFixed(1),
-        spilledMb: +(c.spilledBytes / (1024 * 1024)).toFixed(1),
       });
     }
     return out;
   }
 
-  /*
-   * Apply a change envelope received from Redis pub/sub to the local
-   * collection (if any). Rows that target bases not resident on this node
-   * are ignored — the next `list` call will load them fresh from Postgres.
-   * If any patch step throws (e.g. schema drift between this node and the
-   * publisher) we eagerly invalidate so the next `list` rebuilds cleanly
-   * rather than serving partial state.
-   */
   async applyChange(env: ChangeEnvelope): Promise<void> {
+    const trace = this.env?.getBaseQueryCacheTrace?.() ?? false;
     const collection = this.collections.get(env.baseId);
-    if (this.env?.getBaseQueryCacheTrace?.() ?? false) {
+
+    if (trace) {
       console.log(
         '[cache-trace]',
         JSON.stringify({
@@ -343,6 +306,7 @@ export class BaseQueryCacheService
         }),
       );
     }
+
     if (!collection) return;
 
     try {
@@ -378,16 +342,95 @@ export class BaseQueryCacheService
     }
   }
 
-  private async refreshRowCount(collection: LoadedCollection): Promise<void> {
+  private async ensureLoaded(
-    try {
+    baseId: string,
-      const res = await collection.connection.runAndReadAll(
+    workspaceId: string,
-        'SELECT count(*) AS c FROM rows',
+  ): Promise<LoadedCollection> {
+    const debug = this.env?.getBaseQueryCacheDebug() ?? false;
+    const existing = this.collections.get(baseId);
+
+    const tFind = debug ? Date.now() : 0;
+    const base = await this.baseRepo.findById(baseId);
+    const findMs = debug ? Date.now() - tFind : 0;
+    if (!base) throw new Error(`Base ${baseId} not found`);
+    const freshVersion = (base as any).schemaVersion ?? 1;
+
+    if (existing && existing.schemaVersion === freshVersion) {
+      existing.lastAccessedAt = Date.now();
+      this.recordAccess(baseId);
+      if (debug) {
+        console.log(
+          '[cache-perf]',
+          JSON.stringify({
+            phase: 'ensureLoaded.hit',
+            baseId: baseId.slice(0, 8),
+            findMs,
+          }),
+        );
+      }
+      return existing;
+    }
+
+    if (existing) {
+      await this.runtime.detachBase(existing.schema);
+      this.collections.delete(baseId);
+    }
+
+    const inFlight = this.inFlightLoads.get(baseId);
+    if (inFlight) {
+      const loaded = await inFlight;
+      this.recordAccess(baseId);
+      return loaded;
+    }
+
+    const tLoad = debug ? Date.now() : 0;
+    const promise = (async () => {
+      try {
+        const { maxCollections } = this.configProvider.config;
+        if (this.collections.size >= maxCollections) {
+          await this.evictLru();
+        }
+        const loaded = await this.collectionLoader.load(baseId, workspaceId);
+        this.collections.set(baseId, loaded);
+        return loaded;
+      } finally {
+        this.inFlightLoads.delete(baseId);
+      }
+    })();
+    this.inFlightLoads.set(baseId, promise);
+    const loaded = await promise;
+    const loadMs = debug ? Date.now() - tLoad : 0;
+    this.recordAccess(baseId);
+    if (debug) {
+      console.log(
+        '[cache-perf]',
+        JSON.stringify({
+          phase: 'ensureLoaded.miss',
+          baseId: baseId.slice(0, 8),
+          findMs,
+          loadMs,
+          rows: loaded.rowCount,
+          approxMb: +(loaded.approxBytes / (1024 * 1024)).toFixed(1),
+        }),
       );
-      const row = res.getRowObjects()[0] as { c: bigint | number };
+    }
-      collection.rowCount = Number(row.c);
+    return loaded;
-    } catch {
+  }
-      // swallow — stale rowCount drifts at most by the size of the burst; the
+
-      // next reload-from-Postgres or pubsub event corrects it.
+  private async evictLru(): Promise<void> {
+    let oldestKey: string | null = null;
+    let oldestTime = Number.POSITIVE_INFINITY;
+    for (const [key, col] of this.collections) {
+      if (col.lastAccessedAt < oldestTime) {
+        oldestTime = col.lastAccessedAt;
+        oldestKey = key;
+      }
+    }
+    if (oldestKey) {
+      const col = this.collections.get(oldestKey)!;
+      await this.runtime.detachBase(col.schema);
+      this.collections.delete(oldestKey);
+      this.logger.debug(`Evicted LRU collection ${oldestKey}`);
     }
   }
 
@@ -398,9 +441,10 @@ export class BaseQueryCacheService
     const specs = collection.columns;
     const columnList = specs.map((s) => quoteIdent(s.column)).join(', ');
     const placeholders = specs.map(() => '?').join(', ');
-    const sql = `INSERT OR REPLACE INTO rows (${columnList}) VALUES (${placeholders})`;
+    const sql = `INSERT OR REPLACE INTO ${collection.schema}.rows (${columnList}) VALUES (${placeholders})`;
 
-    const prepared = await collection.connection.prepare(sql);
+    const writer = this.runtime.getWriter();
+    const prepared = await writer.prepare(sql);
     for (let i = 0; i < specs.length; i++) {
       const spec = specs[i];
       const oneBased = i + 1;
@@ -440,8 +484,9 @@ export class BaseQueryCacheService
     collection: LoadedCollection,
     rowId: string,
   ): Promise<void> {
-    const prepared = await collection.connection.prepare(
+    const writer = this.runtime.getWriter();
-      'DELETE FROM rows WHERE id = ?',
+    const prepared = await writer.prepare(
+      `DELETE FROM ${collection.schema}.rows WHERE id = ?`,
     );
     prepared.bindVarchar(1, rowId);
     await prepared.run();
@@ -452,239 +497,133 @@ export class BaseQueryCacheService
     rowId: string,
     position: string,
   ): Promise<void> {
-    const prepared = await collection.connection.prepare(
+    const writer = this.runtime.getWriter();
-      'UPDATE rows SET position = ? WHERE id = ?',
+    const prepared = await writer.prepare(
+      `UPDATE ${collection.schema}.rows SET position = ? WHERE id = ?`,
     );
     prepared.bindVarchar(1, position);
     prepared.bindVarchar(2, rowId);
     await prepared.run();
   }
 
-  private async ensureLoaded(
+  private async refreshRowCount(collection: LoadedCollection): Promise<void> {
-    baseId: string,
+    try {
-    workspaceId: string,
+      const res = await this.runtime.getWriter().runAndReadAll(
-  ): Promise<LoadedCollection> {
+        `SELECT count(*) AS c FROM ${collection.schema}.rows`,
-    const debug = this.env?.getBaseQueryCacheDebug() ?? false;
+      );
-    // TODO(task-7): remove per-request findById once pub/sub invalidation
+      const row = res.getRowObjects()[0] as { c: bigint | number };
-    // keeps collections in sync with schema bumps.
+      collection.rowCount = Number(row.c);
-    const existing = this.collections.get(baseId);
+    } catch {
-
+      // stale rowCount self-corrects on next reload
-    const tFind = debug ? Date.now() : 0;
-    const base = await this.baseRepo.findById(baseId);
-    const findMs = debug ? Date.now() - tFind : 0;
-    if (!base) {
-      throw new Error(`Base ${baseId} not found`);
     }
-    const freshVersion = (base as any).schemaVersion ?? 1;
+  }
 
-    if (existing && existing.schemaVersion === freshVersion) {
+  private recordAccess(baseId: string): void {
-      existing.lastAccessedAt = Date.now();
+    if (!this.configProvider.config.enabled) return;
-      this.recordAccess(baseId);
+    const redis = this.tryGetRedisClient();
-      if (debug) {
+    if (!redis) return;
-        console.log(
+    const nowMs = Date.now();
-          '[cache-perf]',
+    const maxKeep = this.configProvider.config.maxCollections * 10;
-          JSON.stringify({
+    void (async () => {
-            phase: 'ensureLoaded.hit',
+      try {
-            baseId: baseId.slice(0, 8),
+        await redis.zadd('base-query-cache:recent', nowMs, baseId);
-            findMs,
+        await redis.zremrangebyrank(
-          }),
+          'base-query-cache:recent',
+          0,
+          -(maxKeep + 1),
+        );
+      } catch (err) {
+        this.logger.debug(
+          `recordAccess failed for ${baseId}: ${(err as Error).message}`,
         );
       }
-      return existing;
-    }
-
-    if (existing) {
-      this.closeCollection(existing);
-      this.collections.delete(baseId);
-    }
-
-    const inFlight = this.inFlightLoads.get(baseId);
-    if (inFlight) {
-      const loaded = await inFlight;
-      this.recordAccess(baseId);
-      return loaded;
-    }
-
-    const tLoad = debug ? Date.now() : 0;
-    const promise = (async () => {
-      try {
-        const { maxCollections } = this.configProvider.config;
-        if (this.collections.size >= maxCollections) {
-          this.evictLru();
-        }
-        const loaded = await this.collectionLoader.load(baseId, workspaceId);
-        this.collections.set(baseId, loaded);
-        return loaded;
-      } finally {
-        this.inFlightLoads.delete(baseId);
-      }
     })();
-    this.inFlightLoads.set(baseId, promise);
-    const loaded = await promise;
-    const loadMs = debug ? Date.now() - tLoad : 0;
-    this.recordAccess(baseId);
-    if (debug) {
-      console.log(
-        '[cache-perf]',
-        JSON.stringify({
-          phase: 'ensureLoaded.miss',
-          baseId: baseId.slice(0, 8),
-          findMs,
-          loadMs,
-          rows: loaded.rowCount,
-          heapMb: +(loaded.heapBytes / (1024 * 1024)).toFixed(1),
-          spilledMb: +(loaded.spilledBytes / (1024 * 1024)).toFixed(1),
-        }),
-      );
-    }
-    return loaded;
   }
 
-  private evictLru(): void {
+  private tryGetRedisClient(): Redis | null {
-    let oldestKey: string | null = null;
+    if (!this.redisService) return null;
-    let oldestTime = Number.POSITIVE_INFINITY;
-    for (const [key, col] of this.collections) {
-      if (col.lastAccessedAt < oldestTime) {
-        oldestTime = col.lastAccessedAt;
-        oldestKey = key;
-      }
-    }
-    if (oldestKey) {
-      const col = this.collections.get(oldestKey)!;
-      this.closeCollection(col);
-      this.collections.delete(oldestKey);
-      this.logger.debug(`Evicted LRU collection ${oldestKey}`);
-    }
-  }
-
-  private closeCollection(collection: LoadedCollection): void {
     try {
-      collection.connection.closeSync();
+      return this.redisService.getOrNil();
-    } catch (err) {
+    } catch {
-      this.logger.warn(`Failed to close connection: ${(err as Error).message}`);
-    }
-    try {
-      collection.instance.closeSync();
-    } catch (err) {
-      this.logger.warn(`Failed to close instance: ${(err as Error).message}`);
-    }
-  }
-}
-
-// Convert a DuckDB row object back into the BaseRow JSON shape. The builder
-// projects one column per user property; typed columns (DOUBLE, BOOLEAN,
-// TIMESTAMPTZ) round-trip as JS primitives / Date objects. We reconstruct
-// `cells` directly from the per-property columns so the JSON payload matches
-// what Postgres returns.
-function shapeBaseRow(
-  raw: Record<string, unknown>,
-  specs: ColumnSpec[],
-  _sortBuilds: SortBuild[],
-): BaseRow {
-  const cells: Record<string, unknown> = {};
-  for (const spec of specs) {
-    if (!spec.property) continue; // system columns handled below
-    const v = raw[spec.column];
-    cells[spec.property.id] = normaliseCellValue(v, spec);
-  }
-
-  return {
-    id: String(raw.id),
-    baseId: String(raw.base_id),
-    cells: cells as any,
-    position: String(raw.position),
-    creatorId: raw.creator_id == null ? null : String(raw.creator_id),
-    lastUpdatedById:
-      raw.last_updated_by_id == null ? null : String(raw.last_updated_by_id),
-    workspaceId: String(raw.workspace_id),
-    createdAt: toDate(raw.created_at),
-    updatedAt: toDate(raw.updated_at),
-    deletedAt: raw.deleted_at == null ? null : toDate(raw.deleted_at),
-  } as BaseRow;
-}
-
-function normaliseCellValue(value: unknown, spec: ColumnSpec): unknown {
-  if (value == null) return null;
-  switch (spec.ddlType) {
-    case 'VARCHAR':
-      return String(value);
-    case 'DOUBLE':
-      return typeof value === 'number' ? value : Number(value);
-    case 'BOOLEAN':
-      return Boolean(value);
-    case 'TIMESTAMPTZ': {
-      if (value instanceof Date) return value.toISOString();
-      return String(value);
-    }
-    case 'JSON': {
-      if (typeof value === 'string') {
-        try {
-          return JSON.parse(value);
-        } catch {
-          return value;
-        }
-      }
-      return value;
-    }
-    default:
-      return value;
-  }
-}
-
-function toDate(value: unknown): Date {
-  if (value instanceof Date) return value;
-  return new Date(String(value));
-}
-
-// System property type → system column on base_rows (mirrors the map in
-// collection-loader.ts). Kept local to avoid a circular import.
-const SYSTEM_PROPERTY_COLUMN_LOOKUP: Record<string, string> = {
-  [BasePropertyType.CREATED_AT]: 'createdAt',
-  [BasePropertyType.LAST_EDITED_AT]: 'updatedAt',
-  [BasePropertyType.LAST_EDITED_BY]: 'lastUpdatedById',
-};
-
-// Mirror of collection-loader's `readFromRow`, but keyed off a generic event
-// payload (which may be camelCase JSON because it came over EventEmitter /
-// Redis rather than straight from Kysely — both shapes round-trip through
-// here). The function tolerates both the wire shape and the repo shape.
-function readFromRowEvent(
-  row: Record<string, unknown>,
-  spec: ColumnSpec,
-): unknown {
-  switch (spec.column) {
-    case 'id':
-      return row.id;
-    case 'base_id':
-      return row.baseId ?? row.base_id;
-    case 'workspace_id':
-      return row.workspaceId ?? row.workspace_id;
-    case 'creator_id':
-      return row.creatorId ?? row.creator_id;
-    case 'position':
-      return row.position;
-    case 'created_at':
-      return row.createdAt ?? row.created_at;
-    case 'updated_at':
-      return row.updatedAt ?? row.updated_at;
-    case 'last_updated_by_id':
-      return row.lastUpdatedById ?? row.last_updated_by_id;
-    case 'deleted_at':
       return null;
-    case 'search_text':
+    }
-      return '';
   }
-
-  const prop = spec.property;
-  if (!prop) return null;
-
-  const sysColumn = SYSTEM_PROPERTY_COLUMN_LOOKUP[prop.type];
-  if (sysColumn) return row[sysColumn] ?? null;
-
-  const cells = (row.cells as Record<string, unknown> | null) ?? {};
-  return cells[prop.id] ?? null;
 }
 
 function quoteIdent(name: string): string {
   return `"${name.replace(/"/g, '""')}"`;
 }
+
+/*
+ * Convert a DuckDB row object back to the BaseRow JSON shape returned to
+ * API callers. Kept inline (not exported) because it's a pure derivation
+ * from the ColumnSpec list.
+ */
+function shapeBaseRow(
+  raw: Record<string, unknown>,
+  specs: ColumnSpec[],
+  sortBuilds: SortBuild[],
+): BaseRow {
+  const cells: Record<string, unknown> = {};
+  for (const spec of specs) {
+    if (!spec.property) continue;
+    const val = raw[spec.column];
+    if (val == null) continue;
+    if (spec.ddlType === 'JSON' && typeof val === 'string') {
+      try {
+        cells[spec.property.id] = JSON.parse(val);
+      } catch {
+        cells[spec.property.id] = val;
+      }
+    } else {
+      cells[spec.property.id] = val;
+    }
+  }
+  return {
+    id: raw.id as string,
+    baseId: raw.base_id as string,
+    workspaceId: raw.workspace_id as string,
+    creatorId: raw.creator_id as string,
+    position: raw.position as string,
+    createdAt: coerceDate(raw.created_at),
+    updatedAt: coerceDate(raw.updated_at),
+    lastUpdatedById: raw.last_updated_by_id as string,
+    deletedAt: null,
+    cells,
+  } as BaseRow;
+}
+
+function coerceDate(v: unknown): Date {
+  if (v instanceof Date) return v;
+  if (typeof v === 'string') return new Date(v);
+  return new Date(0);
+}
+
+function readFromRowEvent(
+  row: Record<string, unknown>,
+  spec: ColumnSpec,
+): unknown {
+  switch (spec.column) {
+    case 'id':                 return row.id ?? null;
+    case 'base_id':            return row.baseId ?? row.base_id ?? null;
+    case 'workspace_id':       return row.workspaceId ?? row.workspace_id ?? null;
+    case 'creator_id':         return row.creatorId ?? row.creator_id ?? null;
+    case 'position':           return row.position ?? null;
+    case 'created_at':         return row.createdAt ?? row.created_at ?? null;
+    case 'updated_at':         return row.updatedAt ?? row.updated_at ?? null;
+    case 'last_updated_by_id': return row.lastUpdatedById ?? row.last_updated_by_id ?? null;
+    case 'deleted_at':         return null;
+    case 'search_text':        return '';
+  }
+  const prop = spec.property;
+  if (!prop) return null;
+  if (
+    prop.type === BasePropertyType.CREATED_AT ||
+    prop.type === BasePropertyType.LAST_EDITED_AT ||
+    prop.type === BasePropertyType.LAST_EDITED_BY
+  ) {
+    return null;
+  }
+  const cells = (row.cells as Record<string, unknown> | null) ?? {};
+  return cells[prop.id] ?? null;
+}

apps/server/src/core/base/query-cache/collection-loader.ts

@@ -1,13 +1,27 @@
 import { Injectable, Logger } from '@nestjs/common';
-import { DuckDBInstance } from '@duckdb/node-api';
 import { BaseRepo } from '@docmost/db/repos/base/base.repo';
 import { BasePropertyRepo } from '@docmost/db/repos/base/base-property.repo';
 import { buildColumnSpecs } from './column-types';
 import { buildLoaderSql } from './loader-sql';
-import { LoadedCollection } from './query-cache.types';
+import { baseSchemaName } from './schema-name';
-import { PostgresExtensionService } from './postgres-extension.service';
+import { DuckDbRuntime } from './duckdb-runtime';
 import { QueryCacheConfigProvider } from './query-cache.config';
+import { LoadedCollection } from './query-cache.types';
 
+/*
+ * Loads a base into the shared DuckDB runtime as an attached in-memory
+ * database (`<schema>.rows`). Steps:
+ *
+ *   1. Attach a per-base schema.
+ *   2. Run `CREATE TABLE <schema>.rows AS SELECT ... FROM postgres_query(...)`
+ *      via the writer connection — Postgres does the JSONB extraction.
+ *   3. Declare `PRIMARY KEY (id)` on the new table.
+ *   4. Build ART indexes on every indexable column.
+ *   5. Count rows and return a LoadedCollection metadata record.
+ *
+ * Error path: detach the schema before propagating the error, so we don't
+ * leak an empty attached DB into the runtime.
+ */
 @Injectable()
 export class CollectionLoader {
   private readonly logger = new Logger(CollectionLoader.name);
@@ -15,89 +29,54 @@ export class CollectionLoader {
   constructor(
     private readonly baseRepo: BaseRepo,
     private readonly basePropertyRepo: BasePropertyRepo,
-    private readonly pgExtension: PostgresExtensionService,
+    private readonly runtime: DuckDbRuntime,
     private readonly config: QueryCacheConfigProvider,
   ) {}
 
   async load(baseId: string, workspaceId: string): Promise<LoadedCollection> {
-    if (!this.pgExtension.isReady()) {
+    if (!this.runtime.isReady()) {
       throw new Error(
-        `Cannot load collection ${baseId}: postgres extension not ready. ` +
+        `Cannot load collection ${baseId}: duckdb runtime not ready. ` +
-          'Check PostgresExtensionService bootstrap logs.',
+          `Check DuckDbRuntime bootstrap logs.`,
       );
     }
 
     const base = await this.baseRepo.findById(baseId);
-    if (!base) {
+    if (!base) throw new Error(`Base ${baseId} not found`);
-      throw new Error(`Base ${baseId} not found`);
-    }
     const schemaVersion = (base as any).schemaVersion ?? 1;
 
     const properties = await this.basePropertyRepo.findByBaseId(baseId);
     const specs = buildColumnSpecs(properties);
+    const schema = baseSchemaName(baseId);
 
-    const { memoryLimit, threads, tempDirectory } = this.config.config;
+    await this.runtime.attachBase(schema);
-
-    // Ensure the temp directory exists so DuckDB can spill to it.
-    // Swallow errors — if creation fails, DuckDB will fail its own sanity
-    // check and we'll log that instead of crashing here.
-    try {
-      const fs = require('node:fs');
-      fs.mkdirSync(tempDirectory, { recursive: true });
-    } catch {
-      /* swallow */
-    }
-
-    const instance = await DuckDBInstance.create(':memory:', {
-      memory_limit: memoryLimit,
-      threads: String(threads),
-      temp_directory: tempDirectory,
-    });
-    const connection = await instance.connect();
 
     try {
-      await this.pgExtension.configureOnConnection(connection);
+      const writer = this.runtime.getWriter();
 
-      // Disable insertion-order preservation during bulk load — DuckDB's docs
+      const sql = buildLoaderSql(specs, baseId, workspaceId, schema);
-      // explicitly recommend this for memory-pressure on large inserts. Our
-      // loader doesn't depend on the insertion order (we sort via indexes
-      // or keyset cursors later), so this is free memory savings.
-      await connection.run('SET preserve_insertion_order = false');
-
-      // Bulk load via CREATE TABLE AS SELECT. JSONB extraction happens
-      // server-side via the base_cell_* helpers; DuckDB streams typed
-      // columns over COPY BINARY into its vectorized insert path.
-      const sql = buildLoaderSql(specs, baseId, workspaceId);
       if (this.config.config.trace) {
         console.log(
           '[cache-trace]',
           JSON.stringify({
             phase: 'loader.sql',
             baseId,
+            schema,
             length: sql.length,
             sql,
           }),
         );
       }
-      await connection.run(sql);
+      await writer.run(sql);
 
-      // Release the PG connection held by the ATTACH — we're done with
+      await writer.run(`ALTER TABLE ${schema}.rows ADD PRIMARY KEY (id)`);
-      // Postgres; all subsequent queries run purely against the local table.
-      await this.pgExtension.detach(connection);
 
-      // CREATE TABLE AS copies data but not constraints. Re-declare the primary
-      // key so INSERT OR REPLACE (used by applyChange.upsertRow) has a conflict
-      // target. This also backs id lookups with an implicit index, speeding up
-      // per-row upsert/delete.
-      await connection.run('ALTER TABLE rows ADD PRIMARY KEY (id)');
-
-      // Build ART indexes on indexable columns.
       for (const spec of specs) {
         if (!spec.indexable) continue;
         const safe = spec.column.replace(/[^a-zA-Z0-9_]/g, '_');
         const tIdx = this.config.config.trace ? Date.now() : 0;
-        await connection.run(
+        await writer.run(
-          `CREATE INDEX ${quoteIdent(`idx_${safe}`)} ON rows (${quoteIdent(spec.column)})`,
+          `CREATE INDEX ${schema}_${safe}_idx ON ${schema}.rows (${quoteIdent(spec.column)})`,
         );
         if (this.config.config.trace) {
           console.log(
@@ -105,6 +84,7 @@ export class CollectionLoader {
             JSON.stringify({
               phase: 'loader.index',
               baseId,
+              schema,
               column: spec.column,
               ms: Date.now() - tIdx,
             }),
@@ -112,67 +92,49 @@ export class CollectionLoader {
         }
       }
 
-      const countResult = await connection.runAndReadAll(
+      const countResult = await writer.runAndReadAll(
-        'SELECT count(*) AS c FROM rows',
+        `SELECT count(*) AS c FROM ${schema}.rows`,
       );
       const rowCount = Number(
         (countResult.getRowObjects()[0] as { c: bigint | number }).c,
       );
 
-      const memoryResult = await connection.runAndReadAll(
+      const approxBytes = estimateBytes(rowCount, specs.length);
-        `SELECT
-           COALESCE(sum(memory_usage_bytes), 0)::BIGINT AS used_bytes,
-           COALESCE(sum(temporary_storage_bytes), 0)::BIGINT AS spilled_bytes
-         FROM duckdb_memory()`,
-      );
-      const mem = memoryResult.getRowObjects()[0] as {
-        used_bytes: bigint | number;
-        spilled_bytes: bigint | number;
-      };
-      const heapBytes = Number(mem.used_bytes);
-      const spilledBytes = Number(mem.spilled_bytes);
 
       this.logger.debug(
         `Loaded ${rowCount} rows for base ${baseId} ` +
-          `(schemaVersion=${schemaVersion}, heap=${fmtMb(heapBytes)}MB, spilled=${fmtMb(spilledBytes)}MB)`,
+          `(schemaVersion=${schemaVersion}, schema=${schema}, approxMB=${fmtMb(approxBytes)})`,
       );
 
       return {
         baseId,
+        schema,
         schemaVersion,
         columns: specs,
-        instance,
-        connection,
         lastAccessedAt: Date.now(),
         rowCount,
-        heapBytes,
+        approxBytes,
-        spilledBytes,
       };
     } catch (err) {
       try {
-        await this.pgExtension.detach(connection);
+        await this.runtime.detachBase(schema);
-      } catch {
+      } catch { /* swallow */ }
-        /* swallow */
-      }
-      try {
-        connection.closeSync();
-      } catch {
-        /* swallow */
-      }
-      try {
-        instance.closeSync();
-      } catch {
-        /* swallow */
-      }
       throw err;
     }
   }
 }
 
-function quoteIdent(name: string): string {
+function estimateBytes(rowCount: number, columnCount: number): number {
-  return `"${name.replace(/"/g, '""')}"`;
+  // Rough heuristic: ~64 bytes per cell (typed value + ART index entry
+  // overhead). Within 2x of actual for typical schemas; used for
+  // reporting only, not for eviction decisions.
+  return rowCount * columnCount * 64;
 }
 
 function fmtMb(bytes: number): string {
   return (bytes / (1024 * 1024)).toFixed(1);
 }
+
+function quoteIdent(name: string): string {
+  return `"${name.replace(/"/g, '""')}"`;
+}

apps/server/src/core/base/query-cache/postgres-extension.service.spec.ts

@@ -1,129 +0,0 @@
-import { DuckDBInstance } from '@duckdb/node-api';
-import { PostgresExtensionService } from './postgres-extension.service';
-import { QueryCacheConfigProvider } from './query-cache.config';
-
-const makeConfig = (
-  overrides: Partial<QueryCacheConfigProvider['config']> = {},
-): QueryCacheConfigProvider =>
-  ({
-    config: {
-      enabled: true,
-      minRows: 25_000,
-      maxCollections: 50,
-      warmTopN: 50,
-      memoryLimit: '64MB',
-      threads: 2,
-      ...overrides,
-    },
-  }) as unknown as QueryCacheConfigProvider;
-
-const makeEnv = (
-  overrides: { dbUrl?: string } = {},
-): { getDatabaseURL: () => string } => ({
-  getDatabaseURL: () => overrides.dbUrl ?? process.env.DATABASE_URL ?? '',
-});
-
-describe('PostgresExtensionService', () => {
-  it('no-ops when the query cache is disabled', async () => {
-    const svc = new PostgresExtensionService(
-      makeConfig({ enabled: false }),
-      makeEnv() as any,
-    );
-    await expect(svc.onApplicationBootstrap()).resolves.toBeUndefined();
-    expect(svc.isReady()).toBe(false);
-  });
-
-  it('installs and loads the postgres extension on bootstrap when enabled', async () => {
-    const svc = new PostgresExtensionService(makeConfig(), makeEnv() as any);
-    // First run hits the network (extensions.duckdb.org). Subsequent runs read from cache.
-    await svc.onApplicationBootstrap();
-    expect(svc.isReady()).toBe(true);
-  });
-
-  it('configureOnConnection loads the extension and attaches pg in a fresh instance', async () => {
-    const svc = new PostgresExtensionService(makeConfig(), makeEnv() as any);
-    await svc.onApplicationBootstrap();
-
-    const instance = await DuckDBInstance.create(':memory:');
-    const conn = await instance.connect();
-    try {
-      await svc.configureOnConnection(conn);
-      // Smoke-test: query any PG system table. DuckDB's postgres scanner
-      // exposes PG catalog tables under the attached schema's pg_catalog.
-      const res = await conn.runAndReadAll(
-        'SELECT count(*) AS c FROM pg.pg_catalog.pg_database',
-      );
-      const row = res.getRowObjects()[0] as { c: bigint | number };
-      expect(Number(row.c)).toBeGreaterThan(0);
-      await svc.detach(conn);
-    } finally {
-      conn.closeSync();
-      instance.closeSync();
-    }
-  });
-
-  it('detach is idempotent', async () => {
-    const svc = new PostgresExtensionService(makeConfig(), makeEnv() as any);
-    await svc.onApplicationBootstrap();
-
-    const instance = await DuckDBInstance.create(':memory:');
-    const conn = await instance.connect();
-    try {
-      await svc.configureOnConnection(conn);
-      await svc.detach(conn);
-      await expect(svc.detach(conn)).resolves.toBeUndefined();
-    } finally {
-      conn.closeSync();
-      instance.closeSync();
-    }
-  });
-
-  it('configureOnConnection throws a clear error when bootstrap never ran', async () => {
-    const svc = new PostgresExtensionService(makeConfig(), makeEnv() as any);
-    // Intentionally NOT calling onApplicationBootstrap.
-    const instance = await DuckDBInstance.create(':memory:');
-    const conn = await instance.connect();
-    try {
-      await expect(svc.configureOnConnection(conn)).rejects.toThrow(/not ready/i);
-    } finally {
-      conn.closeSync();
-      instance.closeSync();
-    }
-  });
-
-  it('includes the bootstrap failure reason in the not-ready error', async () => {
-    // Force bootstrap to fail by giving the service a broken DB URL so that
-    // LOAD postgres still succeeds but something in the bootstrap path throws.
-    // Simplest reliable failure: monkey-patch the service so its bootstrap
-    // runs a SQL statement that cannot succeed. We accept a small amount of
-    // test-only access by subclassing.
-
-    class BreakingService extends PostgresExtensionService {
-      async onApplicationBootstrap(): Promise<void> {
-        // Call super to keep the gate logic, but sabotage inside by
-        // running INSTALL on a closed connection via a try-wrapper that
-        // throws synchronously and is captured by the parent catch.
-        // Simplest approach: directly set the failure and leave ready=false.
-        (this as any).ready = false;
-        (this as any).bootstrapFailure = 'simulated boot failure XYZ';
-      }
-    }
-
-    const svc = new BreakingService(
-      makeConfig(),
-      makeEnv() as any,
-    );
-    await svc.onApplicationBootstrap();
-
-    const instance = await DuckDBInstance.create(':memory:');
-    const conn = await instance.connect();
-    try {
-      await expect(svc.configureOnConnection(conn)).rejects.toThrow(
-        /simulated boot failure XYZ/,
-      );
-    } finally {
-      conn.closeSync();
-      instance.closeSync();
-    }
-  });
-});

apps/server/src/core/base/query-cache/postgres-extension.service.ts

@@ -1,134 +0,0 @@
-import {
-  Injectable,
-  Logger,
-  OnApplicationBootstrap,
-} from '@nestjs/common';
-import { DuckDBInstance, DuckDBConnection } from '@duckdb/node-api';
-import { QueryCacheConfigProvider } from './query-cache.config';
-import { EnvironmentService } from '../../../integrations/environment/environment.service';
-
-/*
- * Owns the lifecycle of DuckDB's `postgres` extension for the query-cache
- * module. Responsibilities:
- *
- *   1. Install the extension once per process at bootstrap. DuckDB caches the
- *      binary to `$HOME/.duckdb/extensions/...`; subsequent LOADs are offline.
- *      We use the default DuckDB install path (fetches from
- *      `extensions.duckdb.org`) — air-gapped bundling is a separate plan.
- *
- *   2. Configure a fresh DuckDBConnection so a caller can run a single bulk
- *      load query against Postgres via `CREATE TABLE AS SELECT ... FROM pg.*`.
- *      We ATTACH `pg` in READ_ONLY mode using the connection URI inline,
- *      scoped to the DuckDB instance, with no disk state.
- *
- *   3. DETACH on request so the underlying PG connection is released
- *      immediately after the load completes. Per-instance PG attachments are
- *      transient: held only during CREATE TABLE AS, never across queries.
- *
- * When the master query-cache flag is off, this service is a no-op. No
- * instance is created, no network call is made.
- */
-@Injectable()
-export class PostgresExtensionService implements OnApplicationBootstrap {
-  private readonly logger = new Logger(PostgresExtensionService.name);
-  private ready = false;
-  private bootstrapFailure: string | null = null;
-
-  constructor(
-    private readonly config: QueryCacheConfigProvider,
-    private readonly env: EnvironmentService,
-  ) {}
-
-  async onApplicationBootstrap(): Promise<void> {
-    if (!this.config.config.enabled) {
-      this.logger.log('query cache disabled; skipping postgres extension install');
-      return;
-    }
-
-    const bootstrap = await DuckDBInstance.create(':memory:');
-    const conn = await bootstrap.connect();
-    try {
-      // INSTALL writes to $HOME/.duckdb/extensions/<version>/<platform>/.
-      // First ever boot: fetches from extensions.duckdb.org. Subsequent boots:
-      // local-disk no-op.
-      await conn.run('INSTALL postgres');
-      await conn.run('LOAD postgres');
-      this.ready = true;
-      this.logger.log('postgres extension installed and loaded');
-    } catch (err) {
-      const error = err as Error;
-      this.logger.error(
-        `Failed to install/load postgres extension: ${error.message}`,
-      );
-      if (error.stack) this.logger.error(error.stack);
-      // Do NOT rethrow. A failed extension install must not crash the whole
-      // app: the cache service handles this by falling through to Postgres
-      // when `isReady()` returns false (see `CollectionLoader.load`).
-      this.ready = false;
-      this.bootstrapFailure = error.message;
-    } finally {
-      conn.closeSync();
-      bootstrap.closeSync();
-    }
-  }
-
-  isReady(): boolean {
-    return this.ready;
-  }
-
-  /*
-   * Prepares a fresh DuckDBConnection for a bulk-load query against Postgres.
-   * Must be paired with `detach()` once CREATE TABLE AS completes.
-   *
-   * Safe to call on a just-created instance: LOAD reads from the on-disk
-   * extension cache populated at bootstrap (no network call).
-   */
-  async configureOnConnection(conn: DuckDBConnection): Promise<void> {
-    if (!this.ready) {
-      const reason = this.bootstrapFailure
-        ? `: ${this.bootstrapFailure}`
-        : '';
-      throw new Error(
-        `PostgresExtensionService not ready${reason}. Check bootstrap logs.`,
-      );
-    }
-
-    const dbUrl = this.env.getDatabaseURL();
-    if (!dbUrl) {
-      throw new Error('DATABASE_URL is empty; cannot ATTACH from duckdb');
-    }
-
-    await conn.run('LOAD postgres');
-
-    // DuckDB 1.5's `postgres` extension secret syntax expects discrete
-    // HOST/PORT/etc. parameters and rejects the single CONNECTION_STRING
-    // field. Passing the URI directly as ATTACH's first argument keeps the
-    // connection details opaque here and still binds the attachment to this
-    // DuckDB instance only. READ_ONLY guards against the loader accidentally
-    // mutating Postgres.
-    await conn.run(
-      `ATTACH ${escapeSqlString(dbUrl)} AS pg (TYPE POSTGRES, READ_ONLY)`,
-    );
-  }
-
-  /*
-   * Releases the PG connection held by this DuckDBConnection's ATTACH.
-   * Idempotent — safe to call repeatedly, swallows "not attached" errors.
-   */
-  async detach(conn: DuckDBConnection): Promise<void> {
-    try {
-      await conn.run('DETACH pg');
-    } catch (err) {
-      const msg = (err as Error).message ?? '';
-      // DuckDB wording: "Failed to detach database with name \"pg\": database
-      // not found". Also handle older "not attached" / catalog-error shapes.
-      if (!/not attached|not found|does not exist|catalog|failed to detach/i.test(msg)) {
-        throw err;
-      }
-    }
-  }
-}
-
-function escapeSqlString(s: string): string {
-  return `'${s.replace(/'/g, "''")}'`;
-}

apps/server/src/core/base/query-cache/query-cache.module.ts

@@ -1,27 +1,27 @@
 import { Module } from '@nestjs/common';
 import { QueryCacheConfigProvider } from './query-cache.config';
+import { DuckDbRuntime } from './duckdb-runtime';
 import { BaseQueryCacheService } from './base-query-cache.service';
 import { BaseQueryRouter } from './base-query-router';
 import { CollectionLoader } from './collection-loader';
 import { BaseQueryCacheWriteConsumer } from './base-query-cache.write-consumer';
 import { BaseQueryCacheSubscriber } from './base-query-cache.subscriber';
-import { PostgresExtensionService } from './postgres-extension.service';
 
 @Module({
   providers: [
     QueryCacheConfigProvider,
-    PostgresExtensionService,
+    DuckDbRuntime,
+    CollectionLoader,
     BaseQueryCacheService,
     BaseQueryRouter,
-    CollectionLoader,
     BaseQueryCacheWriteConsumer,
     BaseQueryCacheSubscriber,
   ],
   exports: [
     BaseQueryCacheService,
     BaseQueryRouter,
+    DuckDbRuntime,
     QueryCacheConfigProvider,
-    PostgresExtensionService,
   ],
 })
-export class BaseQueryCacheModule {}
+export class QueryCacheModule {}

apps/server/src/core/base/query-cache/query-cache.types.ts

@@ -1,4 +1,3 @@
-import type { DuckDBConnection, DuckDBInstance } from '@duckdb/node-api';
 import type { BaseProperty } from '@docmost/db/types/entity.types';
 
 export type DuckDbColumnType =
@@ -9,31 +8,37 @@ export type DuckDbColumnType =
   | 'JSON';
 
 export type ColumnSpec = {
-  // The uuid of the property (user-defined props) or a stable literal
+  /*
-  // ('id', 'position', 'created_at', 'updated_at', 'last_updated_by_id',
+   * The uuid of the property (user-defined props) or a stable literal
-  //  'deleted_at', 'search_text') for system columns.
+   * ('id', 'position', 'created_at', 'updated_at', 'last_updated_by_id',
+   *  'deleted_at', 'search_text') for system columns.
+   */
   column: string;
   ddlType: DuckDbColumnType;
   indexable: boolean;
-  // For user-defined props we keep the source BaseProperty so callers can
-  // resolve the extraction rule from JSON.
   property?: Pick<BaseProperty, 'id' | 'type' | 'typeOptions'>;
 };
 
+/*
+ * A base held in the shared DuckDB instance. Instead of owning a
+ * `DuckDBInstance` and `DuckDBConnection`, it now just remembers the schema
+ * name of its attached in-memory database. The runtime owns the actual
+ * connections; this is pure metadata.
+ */
 export type LoadedCollection = {
   baseId: string;
+  schema: string;       // e.g. "b_019c69a51d847985a7f68ee2871d8669"
   schemaVersion: number;
   columns: ColumnSpec[];
-  instance: DuckDBInstance;
-  connection: DuckDBConnection;
   lastAccessedAt: number;
-  // cached; set by loader, maintained by applyChange
   rowCount: number;
-  // Memory stats captured immediately after load. Static until next
+  /*
-  // explicit refresh — see `BaseQueryCacheService.refreshMemoryStats` if you
+   * Estimated in-memory footprint, in bytes. DuckDB does not expose
-  // need up-to-date figures after many applyChange() mutations.
+   * per-attached-db memory accounting, so this is a rough heuristic
-  heapBytes: number;
+   * computed at load time: rowCount × columns.length × ~64 bytes. Used
-  spilledBytes: number;
+   * for cache-size reporting; not for eviction decisions.
+   */
+  approxBytes: number;
 };
 
 export type ChangeEnvelope =