Update merge-tree-settings.md

This commit is contained in:
Denny Crane 2023-09-29 15:11:32 -03:00 committed by GitHub
parent d841b8179e
commit 55cd909c29
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -746,14 +746,14 @@ Default value: `0` (limit never applied).
Minimal ratio of the number of _default_ values to the number of _all_ values in a column. Setting this value causes the column to be stored using sparse serializations.
If a column is sparse (contains mostly zeros), ClickHouse can encode it in a sparse format and automatically optimize calculations - the data does not require full decompression during queries. To enable this sparse serialization, define the `ratio_of_defaults_for_sparse_serialization` setting to be less than 1.0. If the value is greater than or equal to 1.0 (the default), then the columns will be always written using the normal full serialization.
If a column is sparse (contains mostly zeros), ClickHouse can encode it in a sparse format and automatically optimize calculations - the data does not require full decompression during queries. To enable this sparse serialization, define the `ratio_of_defaults_for_sparse_serialization` setting to be less than 1.0. If the value is greater than or equal to 1.0, then the columns will be always written using the normal full serialization.
Possible values:
- Float between 0 and 1 to enable sparse serialization
- 1.0 (or greater) if you do not want to use sparse serialization
Default value: `1.0` (sparse serialization is disabled)
Default value: `0.9375` (sparse serialization is disabled)
**Example**