I am trying to find out values stored in a list of keys which match a pattern from redis. I tried using SCAN so that later on i can use MGET to get all the values, The problem is:
SCAN 0 MATCH "foo:bar:*" COUNT 1000
does not return any value whereas
SCAN 0 MATCH "foo:bar:*" COUNT 10000
returns the desired keys.
How do i force SCAN to look through all the existing keys? Do I have to look into lua for this?
With the code below you will scan the 1000 first object from cursor 0
SCAN 0 MATCH "foo:bar:*" COUNT 1000
In result, you will get a new cursor to recall
SCAN YOUR_NEW_CURSOR MATCH "foo:bar:*" COUNT 1000
To scan 1000 next object. Then when you increase COUNT from 1000 to 10000 and retrieve data you scan more keys then in your case match more keys.
To scan the entire list you need to recall SCAN until the cursor give in response return zero (i.e entire scan)
Use INFO command to get your amount of keys like
db0:keys=YOUR_AMOUNT_OF_KEYS,expires=0,avg_ttl=0
Then call
SCAN 0 MATCH "foo:bar:*" COUNT YOUR_AMOUNT_OF_KEYS