Difference between revisions of "Cardinality"

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[[wikipedia:Cardinality]] is generally defined as the number of elements in a [[set]].
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Calculating the exact cardinality of a [[multiset]] requires an amount of memory proportional to the [[cardinality]], which is impractical for very large data sets. The HyperLogLog algorithm is able to estimate cardinalities of > 109 with a typical accuracy (standard error) of 2%, using 1.5 kB of memory.
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You can have lower cardinality (1:5 label-value ratio), standard cardinality (1:80 label-value ratio), or high cardinality (1:10,000 label-value ratio). <ref>https://grafana.com/blog/2022/02/15/what-are-cardinality-spikes-and-why-do-they-matter/</ref>
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[[NRQL]]
 
[[NRQL]]
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* [[High cardinality]]
 
* [[High cardinality]]
 
* [[HyperLogLog]], [[HyperLogLog]]++
 
* [[HyperLogLog]], [[HyperLogLog]]++
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* [[Infinite set]], [[Multiset]]
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== Activities ==
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* Read about cardinality aggregation in [[Elasticsearch]] https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-metrics-cardinality-aggregation.html
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* Read https://docs.newrelic.com/docs/data-apis/ingest-apis/metric-api/NRQL-high-cardinality-metrics/ to understand "What metric is contributing the most cardinality?" and "What impact does a given attribute(s) have to that total cardinality?".
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* [[Prometheus]] https://www.robustperception.io/cardinality-is-key/
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* Read https://valyala.medium.com/high-cardinality-tsdb-benchmarks-victoriametrics-vs-timescaledb-vs-influxdb-13e6ee64dd6b
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== Related ==
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* [[Elasticsearch]]
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* [[New Relic]]
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* [[cortex-tools]]
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== See also ==
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* {{Cardinality}}
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[[Category:Basic concepts in infinite set theory]]

Latest revision as of 12:52, 9 December 2022

wikipedia:Cardinality is generally defined as the number of elements in a set.

Calculating the exact cardinality of a multiset requires an amount of memory proportional to the cardinality, which is impractical for very large data sets. The HyperLogLog algorithm is able to estimate cardinalities of > 109 with a typical accuracy (standard error) of 2%, using 1.5 kB of memory.

You can have lower cardinality (1:5 label-value ratio), standard cardinality (1:80 label-value ratio), or high cardinality (1:10,000 label-value ratio). [1]


NRQL

FROM Metric SELECT cardinality(metric.name) SINCE today RAW



Activities[edit]

Related[edit]

See also[edit]

  • https://grafana.com/blog/2022/02/15/what-are-cardinality-spikes-and-why-do-they-matter/
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