雪花压缩分析
Compression analysis in snowflake
在 redshift 中，我们可以运行“分析压缩”。这为我们提供了有关每列压缩百分比的信息。我们在 snowflake 中有与该命令类似的东西吗？
Snowflake 的一个关键概念是自动存储处理：
When data is loaded into Snowflake, Snowflake reorganizes that data into its internal optimized, compressed, columnar format. Snowflake stores this optimized data in cloud storage.
Snowflake manages all aspects of how this data is stored — the organization, file size, structure, compression, metadata, statistics, and other aspects of data storage are handled by Snowflake. The data objects stored by Snowflake are not directly visible nor accessible by customers; they are only accessible through SQL query operations run using Snowflake.
Benefits of Micro-partitioning
The benefits of Snowflake’s approach to partitioning table data include:
- As the name suggests, micro-partitions are small in size (50 to 500 MB, before compression), which enables extremely efficient DML and fine-grained pruning for faster queries.
...
- Columns are also compressed individually within micro-partitions. Snowflake automatically determines the most efficient compression algorithm for the columns in each micro-partition.
如果“ANALYZE COMPRESSION”的目标是找到潜在的磁盘减少收益，则该过程已经完成。
在 redshift 中，我们可以运行“分析压缩”。这为我们提供了有关每列压缩百分比的信息。我们在 snowflake 中有与该命令类似的东西吗？
Snowflake 的一个关键概念是自动存储处理：
When data is loaded into Snowflake, Snowflake reorganizes that data into its internal optimized, compressed, columnar format. Snowflake stores this optimized data in cloud storage.
Snowflake manages all aspects of how this data is stored — the organization, file size, structure, compression, metadata, statistics, and other aspects of data storage are handled by Snowflake. The data objects stored by Snowflake are not directly visible nor accessible by customers; they are only accessible through SQL query operations run using Snowflake.
Benefits of Micro-partitioning
The benefits of Snowflake’s approach to partitioning table data include:
- As the name suggests, micro-partitions are small in size (50 to 500 MB, before compression), which enables extremely efficient DML and fine-grained pruning for faster queries.
...
- Columns are also compressed individually within micro-partitions. Snowflake automatically determines the most efficient compression algorithm for the columns in each micro-partition.
如果“ANALYZE COMPRESSION”的目标是找到潜在的磁盘减少收益，则该过程已经完成。