await db.$client.[...]

import { upstashCache } from "drizzle-orm/cache/upstash";
import { drizzle } from "drizzle-orm/...";

const db = drizzle(process.env.DB_URL!, {
  cache: upstashCache({
    // 👇 Redis credentials (optional — can also be pulled from env vars)
    url: '<UPSTASH_URL>',
    token: '<UPSTASH_TOKEN>',
    // 👇 Enable caching for all queries by default (optional)
    global: true,
    // 👇 Default cache behavior (optional)
    config: { ex: 60 }
  })
});

import Keyv from "keyv";
export class TestGlobalCache extends Cache {
  private globalTtl: number = 1000;
  // This object will be used to store which query keys were used
  // for a specific table, so we can later use it for invalidation.
  private usedTablesPerKey: Record<string, string[]> = {};
  constructor(private kv: Keyv = new Keyv()) {
    super();
  }
  // For the strategy, we have two options:
  // - 'explicit': The cache is used only when .$withCache() is added to a query.
  // - 'all': All queries are cached globally.
  // The default behavior is 'explicit'.
  override strategy(): "explicit" | "all" {
    return "all";
  }
  // This function accepts query and parameters that cached into key param,
  // allowing you to retrieve response values for this query from the cache.
  override async get(key: string): Promise<any[] | undefined> {
    ...
  }
  // This function accepts several options to define how cached data will be stored:
  // - 'key': A hashed query and parameters.
  // - 'response': An array of values returned by Drizzle from the database.
  // - 'tables': An array of tables involved in the select queries. This information is needed for cache invalidation.
  //
  // For example, if a query uses the "users" and "posts" tables, you can store this information. Later, when the app executes
  // any mutation statements on these tables, you can remove the corresponding key from the cache.
  // If you're okay with eventual consistency for your queries, you can skip this option.
  override async put(
    key: string,
    response: any,
    tables: string[],
    config?: CacheConfig,
  ): Promise<void> {
    ...
  }
  // This function is called when insert, update, or delete statements are executed.
  // You can either skip this step or invalidate queries that used the affected tables.
  //
  // The function receives an object with two keys:
  // - 'tags': Used for queries labeled with a specific tag, allowing you to invalidate by that tag.
  // - 'tables': The actual tables affected by the insert, update, or delete statements,
  //   helping you track which tables have changed since the last cache update.
  override async onMutate(params: {
    tags: string | string[];
    tables: string | string[] | Table<any> | Table<any>[];
  }): Promise<void> {
    ...
  }
}