メタデータは、key: value ペアとして保存されます。value には、文字列、配列、ネストされた key:value ペアなど、さまざまなデータ型があります。たとえば、バケット名は文字列であるものの、バケット オブジェクトのライフサイクル管理の構成はルールの配列です。各ルールには、複数の子 key: value ペアが含まれています。
[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["わかりにくい","hardToUnderstand","thumb-down"],["情報またはサンプルコードが不正確","incorrectInformationOrSampleCode","thumb-down"],["必要な情報 / サンプルがない","missingTheInformationSamplesINeed","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-08-30 UTC。"],[],[],null,["# Bucket metadata\n\n[Get metadata](/storage/docs/getting-bucket-metadata)\n\n[Get bucket size](/storage/docs/getting-bucket-size)\n\nThis page discusses the metadata fields that are stored along with [buckets](/storage/docs/buckets)\nin Cloud Storage.\n\nIntroduction\n------------\n\nCloud Storage buckets have *metadata* associated with them. Metadata\nidentifies properties of the bucket and specifies how the bucket should be\nhandled when it's accessed.\n\nMetadata is stored as `key: value` pairs, where the `value` can take a variety\nof forms, including strings, arrays, or even nested `key:value` pairs. For\nexample, the bucket name is a string, while a bucket Object Lifecycle Management\nconfiguration is an array of rules in which each rule contains several child\n`key: value` pairs.\n\nThe mutability of metadata varies:\n\n- Some you can only view.\n\n- Some you can only set when the bucket is first [created](/storage/docs/creating-buckets), and cannot edit\n or remove.\n\n- Some you can add and edit, but not remove.\n\n- Some you can add, edit, and remove at any time.\n\nNon-editable metadata\n---------------------\n\nThe following metadata is set during bucket creation, and cannot be edited or\nremoved:\n\n- [Bucket name](/storage/docs/buckets#naming)\n\n- The [project](/storage/docs/projects) the bucket is a part of\n\n- Generation number\n\n - A bucket's generation number uniquely identifies the version of the\n bucket even if more than one version of a bucket share the same name.\n\n - A bucket's generation value never changes.\n\n - There is no guarantee that generation numbers increase for successive\n versions, only that each new version has a unique generation number.\n\n - There is no relationship between generation numbers of unrelated buckets.\n\n- Metageneration number\n\n - A bucket's metageneration number uniquely identifies the metadata state of the bucket. The metageneration number is `1` at the time of bucket creation and increases each time you modify the bucket's metadata.\n\nEditable metadata\n-----------------\n\nEditable bucket metadata is metadata whose values you can typically modify at\nany time. In some cases, such as the bucket being subject to an\n[organization policy constraint](/storage/docs/org-policy-constraints), there are restrictions on modifying\ncertain metadata values.\n\n^1^ This metadata cannot be viewed or managed using the XML API.\n\n^2^ You can use the XML API to set this metadata during bucket\ncreation, but not to view or manage this metadata.\n\nWhat's next\n-----------\n\n- Learn how to [view bucket metadata](/storage/docs/getting-bucket-metadata).\n- Read more about [object metadata](/storage/docs/metadata)."]]
