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Clarify sequence bumps perform replicated writes #22039

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Clarify sequence bumps perform replicated writes #22039

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Clarify sequence bumps perform replicated writes
rmloveland Jan 6, 2026
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Update with rafiss feedback (1)
rmloveland Jan 7, 2026
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2 changes: 1 addition & 1 deletion src/current/v26.1/create-sequence.md
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Expand Up @@ -11,7 +11,7 @@ The `CREATE SEQUENCE` [statement]({% link {{ page.version.version }}/sql-stateme

## Considerations

- Using a sequence is slower than [auto-generating unique IDs with the `gen_random_uuid()`, `uuid_v4()` or `unique_rowid()` built-in functions]({% link {{ page.version.version }}/sql-faqs.md %}#how-do-i-auto-generate-unique-row-ids-in-cockroachdb) and is likely to cause performance problems due to [hotspots]({% link {{ page.version.version }}/understand-hotspots.md %}). Incrementing a sequence requires a write to persistent storage, whereas auto-generating a unique ID does not. Therefore, use auto-generated unique IDs unless an incremental sequence is preferred or required. For more information, see [Unique ID best practices]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#unique-id-best-practices).
- Using a sequence is slower than [auto-generating unique IDs with the `gen_random_uuid()`, `uuid_v4()` or `unique_rowid()` built-in functions]({% link {{ page.version.version }}/sql-faqs.md %}#how-do-i-auto-generate-unique-row-ids-in-cockroachdb) and is likely to cause performance problems due to [hotspots]({% link {{ page.version.version }}/understand-hotspots.md %}). Incrementing a sequence requires a write to persistent storage. In CockroachDB, all writes are [replicated and must reach a write quorum]({% link {{ page.version.version }}/architecture/replication-layer.md %}). This means that in [multi-region deployments]({% link {{ page.version.version }}/multiregion-overview.md %}), this can add cross-region latency (for example, in a [region survival]({% link {{ page.version.version }}/multiregion-survival-goals.md %}) configuration) and can become a throughput bottleneck for write-heavy workloads. [Cached sequences](#cache-sequence-values-in-memory-per-node) can reduce the frequency of these writes, though gaps in sequence values may occur if cached values are lost. Auto-generating a unique ID does not require a replicated write. Therefore, use auto-generated unique IDs unless an incremental sequence is preferred or required. For more information, see [Unique ID best practices]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#unique-id-best-practices).
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@florence-crl florence-crl Jan 9, 2026

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non-blocking nit:

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- Using a sequence is slower than [auto-generating unique IDs with the `gen_random_uuid()`, `uuid_v4()` or `unique_rowid()` built-in functions]({% link {{ page.version.version }}/sql-faqs.md %}#how-do-i-auto-generate-unique-row-ids-in-cockroachdb) and is likely to cause performance problems due to [hotspots]({% link {{ page.version.version }}/understand-hotspots.md %}). Incrementing a sequence requires a write to persistent storage. In CockroachDB, all writes are [replicated and must reach a write quorum]({% link {{ page.version.version }}/architecture/replication-layer.md %}). This means that in [multi-region deployments]({% link {{ page.version.version }}/multiregion-overview.md %}), this can add cross-region latency (for example, in a [region survival]({% link {{ page.version.version }}/multiregion-survival-goals.md %}) configuration) and can become a throughput bottleneck for write-heavy workloads. [Cached sequences](#cache-sequence-values-in-memory-per-node) can reduce the frequency of these writes, though gaps in sequence values may occur if cached values are lost. Auto-generating a unique ID does not require a replicated write. Therefore, use auto-generated unique IDs unless an incremental sequence is preferred or required. For more information, see [Unique ID best practices]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#unique-id-best-practices).
- Using a sequence is slower than [auto-generating unique IDs with the `gen_random_uuid()`, `uuid_v4()`, or `unique_rowid()` built-in functions]({% link {{ page.version.version }}/sql-faqs.md %}#how-do-i-auto-generate-unique-row-ids-in-cockroachdb) and is likely to cause performance problems due to [hotspots]({% link {{ page.version.version }}/understand-hotspots.md %}). Incrementing a sequence requires a write to persistent storage. In CockroachDB, all writes are [replicated and must reach a write quorum]({% link {{ page.version.version }}/architecture/replication-layer.md %}). In [multi-region deployments]({% link {{ page.version.version }}/multiregion-overview.md %}), replicated writes can add cross-region latency (for example, in a [region survival]({% link {{ page.version.version }}/multiregion-survival-goals.md %}) configuration) and become a throughput bottleneck for write-heavy workloads. [Cached sequences](#cache-sequence-values-in-memory-per-node) can reduce the frequency of these writes, though gaps in sequence values may occur if cached values are lost. Auto-generating a unique ID does not require a replicated write. Therefore, use auto-generated unique IDs unless an incremental sequence is preferred or required. For more information, refer to [Unique ID best practices]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#unique-id-best-practices).

- A column that uses a sequence can have a gap in the sequence values if a transaction advances the sequence and is then rolled back. Sequence updates are committed immediately and aren't rolled back along with their containing transaction. This is done to avoid blocking concurrent transactions that use the same sequence.
- {% include {{page.version.version}}/performance/use-hash-sharded-indexes.md %}
- By default, you cannot create sequences that are [owned by]({% link {{ page.version.version }}/security-reference/authorization.md %}#object-ownership) columns in tables in other databases. You can enable such sequence creation by setting the `sql.cross_db_sequence_owners.enabled` [cluster setting]({% link {{ page.version.version }}/cluster-settings.md %}) to `true`.
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