Redis Hash: HSCAN

Redis HSCAN Command

HSCAN array of elements contains two elements, a field, and a value, for every returned element of the Hash.

Here are some common uses and scenarios for the "HSCAN" command:

• Large Hash Iteration: Efficiently iterate over large hashes without blocking the server.
• Data Retrieval: Retrieve subsets of fields and values from a hash incrementally.
• Pattern Matching: Filter fields and values based on patterns using the MATCH option.
• Batch Processing: Process hash entries in manageable chunks to avoid overloading the client or server.
• Dynamic Data Inspection: Inspect and analyze hash data progressively, which is useful for debugging or monitoring.

Syntax:

HSCAN key cursor [MATCH pattern] [COUNT count]    

Available since

2.8.0.

Return Value

return a two elements multi-bulk reply, where the first element is a string representing an unsigned 64 bit number (the cursor), and the second element is a multi-bulk with an array of elements.

Return Value Type

Integer

Example: Redis HSCAN

Iteration of an Hash value.

127.0.0.1:6379> HMSET langhash lang1 "PHP" lang2 "JavaScript" lang3 "Python" lang4 "GoLanguage"
OK
127.0.0.1:6379> HSCAN langhash 0
1) "0"
2) 1) "lang1"
   2) "PHP"
   3) "lang2"
   4) "JavaScript"
   5) "lang3"
   6) "Python"
   7) "lang4"
   8) "GoLanguage"

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