Redka stores data in a SQLite database using the following tables:
rkey
---
id integer primary key
key text not null
type integer not null -- 1 string, 2 list, 3 set, 4 hash, 5 sorted set
version integer not null -- incremented when the key value is updated
etime integer -- expiration timestamp in unix milliseconds
mtime integer not null -- modification timestamp in unix milliseconds
len integer -- number of child elements
rstring
---
kid integer not null -- FK -> rkey.id
value blob not null
rlist
---
kid integer not null -- FK -> rkey.id
pos real not null -- is used for ordering, but is not an index
elem blob not null
rset
---
kid integer not null -- FK -> rkey.id
elem blob not null
rhash
---
kid integer not null -- FK -> rkey.id
field text not null
value blob not null
rzset
---
kid integer not null -- FK -> rkey.id
elem blob not null
score real not null
To access the data with SQL, use views instead of tables:
select * from vstring;┌─────┬──────┬───────┬───────┬─────────────────────┐
│ kid │ key │ value │ etime │ mtime │
├─────┼──────┼───────┼───────┼─────────────────────┤
│ 1 │ name │ alice │ │ 2024-04-03 16:58:14 │
│ 2 │ age │ 50 │ │ 2024-04-03 16:34:52 │
└─────┴──────┴───────┴───────┴─────────────────────┘
etime and mtime are in UTC.
There is a separate view for every data type:
vkey vstring vlist vset vhash vzset