• Links:
  • Official docu: Redis data types | Redis
• Basics:
  • Installed through apt-get
  • after that, redis-cli set test 1 etc. immediately work - did it start a server in the background?
    • Ah, it then becomes a service that I can systemctl disable redis-cli etc!
  • Without arguments, redis-cli starts in interactive mode!
    • That has nice hints a la fish shell!
• Transactios:

  > r
  127.0.0.1:6379> multi
  OK
  127.0.0.1:6379> get google
  QUEUED
  127.0.0.1:6379> incr google_accesses
  QUEUED
  127.0.0.1:6379> exec
  1) "http://google.com"
  2) (integer) 1
  127.0.0.1:6379>
  

• Help:
  • help <Tab> autocompletes
  • help @hash

Data structures

Hashes:

# Create a hashset that has field f1 w/ value v1 etc.:
127.0.0.1:6379> hmset myhash f1 v1 f2 v2
OK
127.0.0.1:6379> hgetall myhash
1) "f1"
2) "v1"
3) "f2"
4) "v2"
127.0.0.1:6379> hget myhash f1
"v1"

Operations on hashes:

# We create a hset s_google that has an url and accesses counter
127.0.0.1:6379> hset s_google url url_google accesses 0
(integer) 2
127.0.0.1:6379> hmget s_google url accesses
1) "url_google"
2) "0"
# Increase accesses by 1
127.0.0.1:6379> HINCRBY s_google accesses 1
(integer) 1
127.0.0.1:6379> hmget s_google url accesses
1) "url_google"
2) "1"

Deleting stuff

• DEL key
• FLUSHALL to delete everything

Using files

• cat file.txt | redis-cli --pipe

Sorted sets

127.0.0.1:6379> zadd myss 1 'one' 2 'two'
(integer) 2
127.0.0.1:6379> ZSCORE myss 'one'
"1"
127.0.0.1:6379> ZSCORE myss 'one'

127.0.0.1:6379> get B
"https://www.wikipedia.org"
127.0.0.1:6379> get A
"http://www.openstreetmap.org"
127.0.0.1:6379> ZCARD accesses
(integer) 2
127.0.0.1:6379> ZCARD accesses
(integer) 2
127.0.0.1:6379> ZRANGE accesses 0 40
1) "A"
2) "B"
127.0.0.1:6379> ZRANGE accesses 0 40 withscores
1) "A"
2) "1"
3) "B"
4) "1"
127.0.0.1:6379>