[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[],[],null,["# Cloud Firestore V1 Client - Class ConcurrencyMode (1.53.0)\n\nVersion latestkeyboard_arrow_down\n\n- [1.53.0 (latest)](/php/docs/reference/cloud-firestore/latest/Admin.V1.Database.ConcurrencyMode)\n- [1.52.0](/php/docs/reference/cloud-firestore/1.52.0/Admin.V1.Database.ConcurrencyMode)\n- [1.51.0](/php/docs/reference/cloud-firestore/1.51.0/Admin.V1.Database.ConcurrencyMode)\n- [1.50.0](/php/docs/reference/cloud-firestore/1.50.0/Admin.V1.Database.ConcurrencyMode)\n- [1.48.1](/php/docs/reference/cloud-firestore/1.48.1/Admin.V1.Database.ConcurrencyMode)\n- [1.47.3](/php/docs/reference/cloud-firestore/1.47.3/Admin.V1.Database.ConcurrencyMode)\n- [1.46.0](/php/docs/reference/cloud-firestore/1.46.0/Admin.V1.Database.ConcurrencyMode)\n- [1.45.2](/php/docs/reference/cloud-firestore/1.45.2/Admin.V1.Database.ConcurrencyMode)\n- [1.44.1](/php/docs/reference/cloud-firestore/1.44.1/Admin.V1.Database.ConcurrencyMode)\n- [1.43.3](/php/docs/reference/cloud-firestore/1.43.3/Admin.V1.Database.ConcurrencyMode)\n- [1.40.0](/php/docs/reference/cloud-firestore/1.40.0/Admin.V1.Database.ConcurrencyMode)\n- [1.39.0](/php/docs/reference/cloud-firestore/1.39.0/Admin.V1.Database.ConcurrencyMode)\n- [1.38.0](/php/docs/reference/cloud-firestore/1.38.0/Admin.V1.Database.ConcurrencyMode)\n- [1.37.7](/php/docs/reference/cloud-firestore/1.37.7/Admin.V1.Database.ConcurrencyMode)\n- [1.36.1](/php/docs/reference/cloud-firestore/1.36.1/Admin.V1.Database.ConcurrencyMode)\n- [1.35.0](/php/docs/reference/cloud-firestore/1.35.0/Admin.V1.Database.ConcurrencyMode)\n- [1.34.0](/php/docs/reference/cloud-firestore/1.34.0/Admin.V1.Database.ConcurrencyMode)\n- [1.33.0](/php/docs/reference/cloud-firestore/1.33.0/Admin.V1.Database.ConcurrencyMode)\n- [1.32.0](/php/docs/reference/cloud-firestore/1.32.0/Admin.V1.Database.ConcurrencyMode)\n- [1.31.0](/php/docs/reference/cloud-firestore/1.31.0/Admin.V1.Database.ConcurrencyMode)\n- [1.30.0](/php/docs/reference/cloud-firestore/1.30.0/Admin.V1.Database.ConcurrencyMode)\n- [1.28.0](/php/docs/reference/cloud-firestore/1.28.0/Admin.V1.Database.ConcurrencyMode)\n- [1.27.3](/php/docs/reference/cloud-firestore/1.27.3/Admin.V1.Database.ConcurrencyMode) \nReference documentation and code samples for the Cloud Firestore V1 Client class ConcurrencyMode.\n\nThe type of concurrency control mode for transactions.\n\nProtobuf type `google.firestore.admin.v1.Database.ConcurrencyMode`\n\nNamespace\n---------\n\nGoogle \\\\ Cloud \\\\ Firestore \\\\ Admin \\\\ V1 \\\\ Database\n\nMethods\n-------\n\n### static::name\n\n### static::value\n\nConstants\n---------\n\n### CONCURRENCY_MODE_UNSPECIFIED\n\n Value: 0\n\nNot used.\n\nGenerated from protobuf enum `CONCURRENCY_MODE_UNSPECIFIED = 0;`\n\n### OPTIMISTIC\n\n Value: 1\n\nUse optimistic concurrency control by default. This mode is available\nfor Cloud Firestore databases.\n\nGenerated from protobuf enum `OPTIMISTIC = 1;`\n\n### PESSIMISTIC\n\n Value: 2\n\nUse pessimistic concurrency control by default. This mode is available\nfor Cloud Firestore databases.\n\nThis is the default setting for Cloud Firestore.\n\nGenerated from protobuf enum `PESSIMISTIC = 2;`\n\n### OPTIMISTIC_WITH_ENTITY_GROUPS\n\n Value: 3\n\nUse optimistic concurrency control with entity groups by default.\n\nThis is the only available mode for Cloud Datastore.\nThis mode is also available for Cloud Firestore with Datastore Mode but\nis not recommended.\n\nGenerated from protobuf enum `OPTIMISTIC_WITH_ENTITY_GROUPS = 3;`"]]