Redis Aggregation Query

Redis is an open-source high-performance key value pair storage database. It stores data in memory and supports multiple data structures and aggregation operations. Redis supports the following aggregation query operations: 1. Fuzzy query through KEYS: The KEYS command can be used to query a specified list of key names through fuzzy matching. For example, suppose we have the following data structures and data: SET user:1 "Alice" SET user:2 "Bob" SET user:3 "Charlie" We can use the following command to aggregate queries: KEYS user:* The above command will return all key names starting with "user:", namely ["user: 1", "user: 2", "user: 3"]. 2. Query through SCAN iteration: The SCAN command allows for iterative queries. Compared to KEYS, SCAN traverses all key names in a cursor like manner. This approach can avoid performance issues caused by large-scale datasets. For example, suppose we have the following data structures and data: SET user:1 "Alice" SET user:2 "Bob" SET user:3 "Charlie" We can use the following command to aggregate queries: SCAN 0 MATCH user:* The above command will return all key names starting with "user:", namely ["user: 1", "user: 2", "user: 3"]. 3. Use HASH data structure for aggregation queries: Using the HASH data structure, multiple field values can be associated with a key for aggregate queries. For example, suppose we have the following data structures and data: HMSET user:1 name "Alice" age 20 HMSET user:2 name "Bob" age 25 HMSET user:3 name "Charlie" age 30 We can use the following command to aggregate queries: HGETALL user:1 The above command will return all fields and values of the specified key, namely {"name": "Alice", "age": "20"}. 4. Use other data structures (such as List, Set, Sorted Set) for aggregation queries: Redis also provides other data structures, such as List, Set, Sorted Set, which can also be used for aggregate queries. For example, suppose we have the following data structures and data: LPUSH transactions 10 LPUSH transactions 20 LPUSH transactions 30 We can use the following command to aggregate queries: LRANGE transactions 0 -1 The above command will return all elements of the specified list, namely ["30", "20", "10"]. It should be noted that Redis is not a traditional relational database, it is mainly used for caching and high-performance data read and write. Although Redis supports some aggregation query operations, its aggregation function is relatively weak and cannot provide complex aggregation operations and grouping statistics. If complex aggregation queries and analysis are required, it may be necessary to consider using other databases or using Redis in combination with other databases.