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42 lines
1.1 KiB
Markdown
42 lines
1.1 KiB
Markdown
---
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slug: /en/operations/system-tables/projections
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---
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# projections
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Contains information about existing projections in all the tables.
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Columns:
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- `database` ([String](../../sql-reference/data-types/string.md)) — Database name.
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- `table` ([String](../../sql-reference/data-types/string.md)) — Table name.
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- `name` ([String](../../sql-reference/data-types/string.md)) — Projection name.
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- `type` ([Enum](../../sql-reference/data-types/enum.md)) — Projection type ('Normal' = 0, 'Aggregate' = 1).
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- `sorting_key` ([Array(String)](../../sql-reference/data-types/array.md)) — Projection sorting key.
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- `query` ([String](../../sql-reference/data-types/string.md)) — Projection query.
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**Example**
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```sql
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SELECT * FROM system.projections LIMIT 2 FORMAT Vertical;
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```
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```text
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Row 1:
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──────
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database: default
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table: landing
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name: improved_sorting_key
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type: Normal
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sorting_key: ['user_id','date']
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query: SELECT * ORDER BY user_id, date
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Row 2:
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──────
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database: default
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table: landing
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name: agg_no_key
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type: Aggregate
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sorting_key: []
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query: SELECT count()
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```
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