bitop.md

acl_categories	arguments	arity	categories	command_flags	complexity	description	group	hidden	key_specs	linkTitle	railroad_diagram	since	summary	syntax_fmt	title
@write @bitmap @slow	arguments name type display_text name token type and and AND pure-token display_text name token type or or OR pure-token display_text name token type xor xor XOR pure-token display_text name token type not not NOT pure-token operation oneof display_text key_spec_index name type destkey 0 destkey key display_text key_spec_index multiple name type key 1 true key key	-4	docs develop stack oss rs rc oss kubernetes clients	write denyoom	O(N)	Performs bitwise operations on multiple strings, and stores the result.	bitmap	false	OW begin_search find_keys update true spec type index 2 index spec type keystep lastkey limit 1 0 0 range true RO access begin_search find_keys true true spec type index 3 index spec type keystep lastkey limit 1 -1 0 range	BITOP	/images/railroad/bitop.svg	2.6.0	Performs bitwise operations on multiple strings, and stores the result.	BITOP <AND | OR | XOR | NOT | DIFF | DIFF1 | ANDOR | ONE> destkey key [key ...]	BITOP

{{< note >}} This command is affected by cross-slot operations. See the [multi-key operations]({{< relref "/develop/using-commands/multi-key-operations" >}}) page for more information. {{< /note >}}

Perform a bitwise operation between multiple keys (containing string values) and store the result in the destination key.

The BITOP command supports eight bitwise operations: AND, OR, XOR, NOT, DIFF, DIFF1, ANDOR, and ONE. The valid forms to call the command are:

• BITOP AND destkey srckey1 srckey2 srckey3 ... srckeyN

  A bit in destkey is set only if it is set in all source bitmaps.

• BITOP OR destkey srckey1 srckey2 srckey3 ... srckeyN

  A bit in destkey is set only if it is set in at least one source bitmap.

• BITOP XOR destkey srckey1 srckey2 srckey3 ... srckeyN

  Mostly used with two source bitmaps, a bit in destkey is set only if its value differs between the two source bitmaps.

• BITOP NOT destkey srckey

  NOT is a unary operator and only supports a single source bitmap; set the bit to the inverse of its value in the source bitmap.

• BITOP DIFF destkey X [Y1 Y2 ...] ¹

  A bit in destkey is set if it is set in X, but not in any of Y1, Y2, ... .

• BITOP DIFF1 destkey X [Y1 Y2 ...] ¹

  A bit in destkey is set if it is set in one or more of Y1, Y2, ..., but not in X.

• BITOP ANDOR destkey X [Y1 Y2 ...] ¹

  A bit in destkey is set if it is set in X and also in one or more of Y1, Y2, ....

• BITOP ONE destkey X1 [X2 X3 ...] ¹

  A bit in destkey is set if it is set in exactly one of X1, X2, ....

The result of each operation is always stored at destkey.

1. Added in Redis 8.2.

Handling of strings with different lengths

When an operation is performed between strings having different lengths, all the strings shorter than the longest string in the set are treated as if they were zero-padded up to the length of the longest string.

The same holds true for non-existent keys, that are considered as a stream of zero bytes up to the length of the longest string.

Examples

1. Basic usage example using the AND operator:

{{% redis-cli %}} BITFIELD key1 SET i8 #0 255 BITFIELD key2 SET i8 #0 85 BITOP AND dest key1 key2 BITFIELD dest GET i8 #0 {{% /redis-cli %}}

2. Suppose you want to expose people to a book-related ad. The target audience is people who love to read books and are interested in fantasy, adventure, or science fiction. Assume you have the following bitmaps:

• LRB - people who love to read books.
• B:F - people interested in fantasy.
• B:A - people interested in adventure.
• B:SF - people interested in science fiction.

To create a bitmap representing the target audience, use the following command:

BITOP ANDOR TA LRB B:F B:A B:SF

Pattern: real time metrics using bitmaps

BITOP is a good complement to the pattern documented in the [BITCOUNT]({{< relref "/commands/bitcount" >}}) command documentation. Different bitmaps can be combined in order to obtain a target bitmap where the population counting operation is performed.

See the article called "Fast easy realtime metrics using Redis bitmaps" for an interesting use cases.

Performance considerations

BITOP is a potentially slow command as it runs in O(N) time. Care should be taken when running it against long input strings.

For real-time metrics and statistics involving large inputs a good approach is to use a replica (with replica-read-only option enabled) where the bit-wise operations are performed to avoid blocking the master instance.

Redis Enterprise and Redis Cloud compatibility

Redis Enterprise	Redis Cloud	Notes
✅ Standard ✅ Active-Active	✅ Standard ✅ Active-Active

Return information

{{< multitabs id="bitop-return-info" tab1="RESP2" tab2="RESP3" >}}

Integer reply: the size of the string stored in the destination key is equal to the size of the longest input string.

-tab-sep-

Integer reply: the size of the string stored in the destination key is equal to the size of the longest input string.

{{< /multitabs >}}