Kora provides a built-in JSON document database with secondary indexes, query support, and field-level operations. Documents are stored using a space-efficient binary format.
DOC.CREATE
Create a new document collection.
Syntax
DOC.CREATE collection [COMPRESSION profile]
The name of the collection to create
Optional compression profile name (e.g., “lz4”)
OK if the collection was created successfully
redis-cli> DOC.CREATE users
OK
redis-cli> DOC.CREATE products COMPRESSION lz4
OK
DOC.DROP
Drop a document collection and all its data.
Syntax
The name of the collection to drop
OK if the collection was dropped successfully
redis-cli> DOC.DROP users
OK
DOC.SET
Insert or replace a document in a collection.
Syntax
DOC.SET collection doc_id json
The document ID (unique within the collection)
The JSON document payload
OK if the document was set successfully
redis-cli> DOC.SET users user:1 '{"name":"Alice","age":30,"city":"NYC"}'
OK
redis-cli> DOC.SET users user:2 '{"name":"Bob","age":25,"city":"LA"}'
OK
DOC.GET
Retrieve a document from a collection.
Syntax
DOC.GET collection doc_id [FIELDS path ...]
Optional field paths to project (dotted notation)
The JSON document, or null if not found
redis-cli> DOC.GET users user:1
"{\"name\":\"Alice\",\"age\":30,\"city\":\"NYC\"}"
redis-cli> DOC.GET users user:1 FIELDS name city
"{\"name\":\"Alice\",\"city\":\"NYC\"}"
redis-cli> DOC.GET users user:99
(nil)
DOC.MSET
Batch insert or replace multiple documents.
Syntax
DOC.MSET collection doc_id json [doc_id json ...]
The JSON document for the corresponding ID
OK if all documents were set successfully
redis-cli> DOC.MSET users user:1 '{"name":"Alice"}' user:2 '{"name":"Bob"}'
OK
DOC.MGET
Batch retrieve multiple documents.
Syntax
DOC.MGET collection doc_id [doc_id ...]
One or more document IDs to retrieve
Array of JSON documents (null for missing documents)
redis-cli> DOC.MGET users user:1 user:2 user:99
1) "{\"name\":\"Alice\",\"age\":30}"
2) "{\"name\":\"Bob\",\"age\":25}"
3) (nil)
DOC.UPDATE
Apply field-level mutations to a document.
Syntax
DOC.UPDATE collection doc_id <mutation...>
One or more mutations: SET path value | DEL path | INCR path delta | PUSH path value | PULL path value
OK if the update was successful
redis-cli> DOC.SET users user:1 '{"name":"Alice","age":30,"tags":["admin"]}'
OK
redis-cli> DOC.UPDATE users user:1 SET city "NYC" INCR age 1
OK
redis-cli> DOC.UPDATE users user:1 PUSH tags "verified" DEL temp
OK
redis-cli> DOC.GET users user:1
"{\"name\":\"Alice\",\"age\":31,\"city\":\"NYC\",\"tags\":[\"admin\",\"verified\"]}"
- SET path value - Set a field to a JSON value
- DEL path - Delete a field
- INCR path delta - Increment a numeric field
- PUSH path value - Append to an array field
- PULL path value - Remove matching values from an array field
DOC.DEL
Delete a document from a collection.
Syntax
DOC.DEL collection doc_id
The document ID to delete
1 if the document was deleted, 0 if it did not exist
redis-cli> DOC.DEL users user:1
(integer) 1
redis-cli> DOC.DEL users user:99
(integer) 0
DOC.EXISTS
Check if a document exists in a collection.
Syntax
DOC.EXISTS collection doc_id
1 if the document exists, 0 otherwise
redis-cli> DOC.EXISTS users user:1
(integer) 1
redis-cli> DOC.EXISTS users user:99
(integer) 0
DOC.CREATEINDEX
Create a secondary index on a field.
Syntax
DOC.CREATEINDEX collection field type
The field path (dotted notation)
Index type: hash, sorted, array, or unique
OK if the index was created successfully
redis-cli> DOC.CREATEINDEX users email unique
OK
redis-cli> DOC.CREATEINDEX users age sorted
OK
redis-cli> DOC.CREATEINDEX users tags array
OK
- hash - Equality queries (field = value)
- sorted - Range queries (field > value, field < value)
- array - Array contains queries
- unique - Hash index with uniqueness constraint
DOC.DROPINDEX
Drop a secondary index.
Syntax
DOC.DROPINDEX collection field
The field path of the index to drop
OK if the index was dropped successfully
redis-cli> DOC.DROPINDEX users age
OK
DOC.INDEXES
List all indexes on a collection.
Syntax
Return value
Array of index definitions (field, type pairs)
redis-cli> DOC.INDEXES users
1) "email"
2) "unique"
3) "age"
4) "sorted"
DOC.FIND
Query documents using a WHERE expression.
Syntax
DOC.FIND collection WHERE expr [ORDER BY field [ASC|DESC]] [PROJECT f1 f2 ...] [LIMIT n] [OFFSET n]
Filter expression (e.g., “age > 25 AND city = ‘NYC’”)
Sort order (default: ASC)
Fields to include in results
Maximum number of results to return
Number of results to skip
Array of matching JSON documents
redis-cli> DOC.FIND users WHERE "age > 25"
1) "{\"name\":\"Alice\",\"age\":30,\"city\":\"NYC\"}"
2) "{\"name\":\"Charlie\",\"age\":28,\"city\":\"SF\"}"
redis-cli> DOC.FIND users WHERE "city = 'NYC' AND age >= 30" ORDER BY age DESC LIMIT 10
1) "{\"name\":\"Alice\",\"age\":30,\"city\":\"NYC\"}"
redis-cli> DOC.FIND users WHERE "age > 20" PROJECT name age
1) "{\"name\":\"Alice\",\"age\":30}"
2) "{\"name\":\"Bob\",\"age\":25}"
- Comparisons:
=, !=, >, >=, <, <=
- Logical:
AND, OR, NOT
- String literals:
'value' or "value"
- Numeric literals:
123, 45.67
- Boolean literals:
true, false
- Null:
null
DOC.COUNT
Count documents matching a WHERE expression.
Syntax
DOC.COUNT collection WHERE expr
The number of matching documents
redis-cli> DOC.COUNT users WHERE "age > 25"
(integer) 42
redis-cli> DOC.COUNT users WHERE "city = 'NYC'"
(integer) 15
DOC.INFO
Get metadata about a collection.
Syntax
Return value
Array of key-value pairs with collection metadata
redis-cli> DOC.INFO users
1) "document_count"
2) (integer) 100
3) "indexes"
4) (integer) 2
5) "compression"
6) "lz4"
DOC.DICTINFO
Get dictionary statistics for a collection.
Syntax
Return value
Dictionary compression statistics
redis-cli> DOC.DICTINFO users
1) "unique_keys"
2) (integer) 15
3) "compression_ratio"
4) "2.4"
DOC.STORAGE
Get storage statistics for a collection.
Syntax
Return value
Storage size and efficiency metrics
redis-cli> DOC.STORAGE users
1) "bytes_used"
2) (integer) 524288
3) "documents"
4) (integer) 1000