estimateCompressionRatio

estimateCompressionRatio

Estimates the compression ratio of a given column without compressing it.

Syntax

Arguments

• column - Column of any type

Parameters

• codec - String containing a compression codec.
• block_size_bytes - Block size of compressed data. This is similar to setting both max_compress_block_size and min_compress_block_size. The default value is 1 MiB (1048576 bytes).

Both parameters are optional.

Returned values

• Returns an estimate compression ratio for the given column.

Type: Float64.

Examples

Input table:

Query:

Result:

备注

The result above will differ based on the default compression codec of the server. See Column Compression Codecs.

Query:

Result: