Top Redis interview questions and answers
1. What is Redis?
Redis is an open source released under BSD licensed, in-memory data structure store, it can be used as a database, cache and message broker.
2. List the data structures supported by Redis.
Redis supports following Data Structures
- Sorted sets with range queries
- Geospatial indexes with radius queries
3. List some advantages of Redis?
Following are some advantages of Redis
- Exceptionally Faster than others
- Supports for rich data types like Hashes, Sets, bitmaps
- Rich client-side library.
- Support for server-side locking.
- Operations are atomic.
4. List some commonly used Redis commands?
Some commonly used Redis commands list
|APPEND||Append a value to a key|
|AUTH||Authenticate to the server|
|BGREWRITEAOF||Asynchronously rewrite the append-only file|
|BGSAVE||Asynchronously save the dataset to disk|
|BITCOUNT||Count set bits in a string|
|CLIENT LIST||Get the list of client connections|
|CLUSTER INFO||Provides info about Redis Cluster node state|
Read more from Redis Commands List
5. In which language Redis is written?
Redis is NoSql based Key-value Database, which is written in ANSI C
6.List some Redis Clients supported by PHP?
Below are some Redis Clients supported by PHP Programming Language
- PHP Redis implementation / wrapper
- PHP Sentinel Client
7. What is redis-cli.
redis-cli is the Redis command line interface, a simple program that allows to send commands to Redis, and read the replies sent by the server, directly from the terminal.
8. Explain REPL
REPL stands for Read Eval Print Loop. It an interactive mode where the user types commands and get replies.