# Delta-authoritative tables · storage · 2021

Revision 1 (11 October 2026) · Modeled snapshot · through 8 October 2026.

All figures are research-informed estimates of analytical activity. Significant errors may remain; decimal places do not imply measurement precision.

4.98% of the full storage layer.

[Delta-authoritative tables](https://history.columnar.tech/technologies/storage/delta.md): historical names and annual shares.

## Management within Delta

Unmanaged means customer-managed; managed means vendor-managed table maintenance. These are subdivisions of the parent, with no separate engine connections.

| Subdivision | Share of parent | Share of full storage layer |
| --- | --- | --- |
| Unmanaged | 100% | 4.98% |
| Managed | 0% | 0% |

## Contributions by compute engine

Each figure is a share of the full storage layer.

| Engine | Share of full storage layer | Engine connections |
| --- | --- | --- |
| [Databricks](https://history.columnar.tech/technologies/compute/databricks.md) | 3.3% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/databricks.md) |
| [Apache Spark (including Amazon EMR, Synapse Spark, and Google Cloud Dataproc)](https://history.columnar.tech/technologies/compute/spark.md) | 1.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/spark.md) |
| [Trino](https://history.columnar.tech/technologies/compute/trino.md) | 0.2% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/trino.md) |
| [Amazon Athena](https://history.columnar.tech/technologies/compute/athena.md) | 0.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/athena.md) |
| [Amazon Redshift](https://history.columnar.tech/technologies/compute/redshift.md) | 0.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/redshift.md) |
| [SQL Server / Synapse](https://history.columnar.tech/technologies/compute/sqlserver.md) | <0.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/sqlserver.md) |
| [Presto](https://history.columnar.tech/technologies/compute/presto.md) | <0.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/presto.md) |
| [Dremio](https://history.columnar.tech/technologies/compute/dremio.md) | <0.1% | [Inspect engine](https://history.columnar.tech/connections/2021/compute/dremio.md) |

[All percentages for 2021](https://history.columnar.tech/years/2021.md)

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