{ "id": "ts.decrby", "title": "TS.DECRBY", "url": "https://redis.io/docs/latest/commands/ts.decrby/", "summary": "Decrease the value of the sample with the maximum existing timestamp, or create a new sample with a value equal to the value of the sample with the maximum existing timestamp with a given decrement", "tags": [ "docs", "develop", "stack", "oss", "rs", "rc", "oss", "kubernetes", "clients" ], "last_updated": "2026-04-01T08:10:08-05:00", "page_type": "content", "content_hash": "70b6f7db1d5294d780383d063648a618c58ebe8f0eb6af604dc60b8cdc87e5cd", "sections": [ { "id": "overview", "title": "Overview", "role": "overview", "text": "Decrease the value of the sample with the maximum existing timestamp, or create a new sample with a value equal to the value of the sample with the maximum existing timestamp with a given decrement\n\n[Examples](#examples)" }, { "id": "required-arguments", "title": "Required arguments", "role": "content", "text": "
key \n\nis key name for the time series.\n
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subtrahend \n\nis numeric value of the subtrahend (double). An error is returned if the subtrahend is NaN.\n
\n\nNotes\n- When specified key does not exist, a new time series is created.\n- You can use this command as a counter or gauge that automatically gets history as a time series.\n- If a policy for handling duplicate samples (`IGNORE`) is defined for this time series - `TS.DECRBY` operations are affected as well (sample additions/modifications can be filtered).\n- Explicitly adding samples to a compacted time series (using [`TS.ADD`](), [`TS.MADD`](), [`TS.INCRBY`](), or `TS.DECRBY`) may result in inconsistencies between the raw and the compacted data. The compaction process may override such samples.\n" }, { "id": "optional-arguments", "title": "Optional arguments", "role": "parameters", "text": "
TIMESTAMP timestamp \n\nis Unix time (integer, in milliseconds) specifying the sample timestamp or `*` to set the sample timestamp to the Unix time of the server's clock.\n\nUnix time is the number of milliseconds that have elapsed since 00:00:00 UTC on 1 January 1970, the Unix epoch, without adjustments made due to leap seconds.\n\n`timestamp` must be equal to or higher than the maximum existing timestamp. When equal, the value of the sample with the maximum existing timestamp is decreased. If it is higher, a new sample with a timestamp set to `timestamp` is created, and its value is set to the value of the sample with the maximum existing timestamp minus `subtrahend`. \n\nIf the time series is empty, the value is set to `subtrahend`.\n\nWhen not specified, the timestamp is set to the Unix time of the server's clock.\n\nNaN Handling (Redis 8.6+): An error is returned if the current value at the maximum existing timestamp is NaN.\n
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RETENTION retentionPeriod \n\nis maximum retention period, compared to the maximum existing timestamp, in milliseconds.\n\nUse it only if you are creating a new time series. It is ignored if you are adding samples to an existing time series. See `RETENTION` in [`TS.CREATE`]().\n
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ENCODING enc \n\nspecifies the series sample encoding format.\n\nUse it only if you are creating a new time series. It is ignored if you are adding samples to an existing time series. See `ENCODING` in [`TS.CREATE`]().\n
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CHUNK_SIZE size \n\nis memory size, in bytes, allocated for each data chunk.\n\nUse it only if you are creating a new time series. It is ignored if you are adding samples to an existing time series. See `CHUNK_SIZE` in [`TS.CREATE`]().\n
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DUPLICATE_POLICY policy\n\nis policy for handling insertion ([`TS.ADD`]() and [`TS.MADD`]()) of multiple samples with identical timestamps.\n\nUse it only if you are creating a new time series. It is ignored if you are adding samples to an existing time series. See `DUPLICATE_POLICY` in [`TS.CREATE`]().\n
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IGNORE ignoreMaxTimediff ignoreMaxValDiff \n\nis the policy for handling duplicate samples. A new sample is considered a duplicate and is ignored if the following conditions are met:\n\n - The time series is not a compaction;\n - The time series' `DUPLICATE_POLICY` IS `LAST`;\n - The sample is added in-order (`timestamp ≥ max_timestamp`);\n - The difference of the current timestamp from the previous timestamp (`timestamp - max_timestamp`) is less than or equal to `IGNORE_MAX_TIME_DIFF`;\n - The absolute value difference of the current value from the value at the previous maximum timestamp (`abs(value - value_at_max_timestamp`) is less than or equal to `IGNORE_MAX_VAL_DIFF`.\n\nwhere `max_timestamp` is the timestamp of the sample with the largest timestamp in the time series, and `value_at_max_timestamp` is the value at `max_timestamp`.\n\nWhen not specified: set to the global [IGNORE_MAX_TIME_DIFF]() and [IGNORE_MAX_VAL_DIFF](), which are, by default, both set to 0.\n\nThese parameters are used when creating a new time series to set the per-key parameters, and are ignored when called with an existing time series (the existing per-key configuration parameters are used).\n
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LABELS [{label value}...] \n\nis set of label-value pairs that represent metadata labels of the key and serve as a secondary index.\n\nUse it only if you are creating a new time series. It is ignored if you are adding samples to an existing time series. See `LABELS` in [`TS.CREATE`]().\n
\n\nNotes\n- You can use this command to create a new time series and add a sample to it in a single command.\n `RETENTION`, `ENCODING`, `CHUNK_SIZE`, `DUPLICATE_POLICY`, `IGNORE`, and `LABELS` are used only when creating a new time series, and ignored when adding or modifying samples in an existing time series.\n- Setting `RETENTION` and `LABELS` introduces additional time complexity.\n" }, { "id": "redis-software-and-redis-cloud-compatibility", "title": "Redis Software and Redis Cloud compatibility", "role": "content", "text": "| Redis
Software | Redis
Cloud | Notes |\n|:----------------------|:-----------------|:------|\n| ✅ Supported
| ✅ Flexible & Annual
✅ Free & Fixed | |" }, { "id": "return-information", "title": "Return information", "role": "returns", "text": "**RESP2:**\n\nOne of the following:\n* [Integer reply](): the timestamp of the upserted sample. If the sample is ignored (see `IGNORE` in [`TS.CREATE`]()), the reply will be the largest timestamp in the time series.\n* [Simple error reply]() in these cases: invalid arguments, wrong key type, or when `timestamp` is not equal to or higher than the maximum existing timestamp.\n\n**RESP3:**\n\nOne of the following:\n* [Integer reply](): the timestamp of the upserted sample. If the sample is ignored (see `IGNORE` in [`TS.CREATE`]()), the reply will be the largest timestamp in the time series.\n* [Simple error reply]() in these cases: invalid arguments, wrong key type, or when `timestamp` is not equal to or higher than the maximum existing timestamp." }, { "id": "see-also", "title": "See also", "role": "related", "text": "[`TS.INCRBY`]() | [`TS.CREATE`]()" }, { "id": "related-topics", "title": "Related topics", "role": "related", "text": "[RedisTimeSeries]()" } ], "examples": [] }