From 5a6428432f3b40e02c1cb5b4765fb1e75766f4d0 Mon Sep 17 00:00:00 2001 From: filimonov <1549571+filimonov@users.noreply.github.com> Date: Fri, 26 Jan 2024 19:09:48 +0100 Subject: [PATCH] Update _index.md --- content/en/altinity-kb-schema-design/codecs/_index.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/content/en/altinity-kb-schema-design/codecs/_index.md b/content/en/altinity-kb-schema-design/codecs/_index.md index 29f541ff57..ffb29352ab 100644 --- a/content/en/altinity-kb-schema-design/codecs/_index.md +++ b/content/en/altinity-kb-schema-design/codecs/_index.md @@ -10,15 +10,15 @@ description: > | LZ4 | Any | Used by default. Extremely fast; good compression; balanced speed and efficiency | | ZSTD(level) | Any | Good compression; pretty fast; best for high compression needs. Don't use levels highter than 3. | | LZ4HC(level) | Any | LZ4 High Compression algorithm with configurable level; slower but better compression than LZ4, but decmpression is still fast. | -| Delta | Integer Types, Time Series Data | Preprocessor (should be followed by some compression coded). Stores difference between neighboring values; good for monotonically increasing data. | +| Delta | Integer Types, Time Series Data | Preprocessor (should be followed by some compression codec). Stores difference between neighboring values; good for monotonically increasing data. | | DoubleDelta | Integer Types, Time Series Data | Stores difference between neighboring delta values; suitable for time series data | | Gorilla | Floating Point Types | Calculates XOR between current and previous value; suitable for slowly changing numbers | -| T64 | Integer, Enum, Date, DateTime | Preprocessor (should be followed by some compression coded). Crops unused high bits; puts them into a 64x64 bit matrix; optimized for 64-bit data types | -| GCD | Integer Numbers | Preprocessor (should be followed by some compression coded). Greatest common divisor compression; divides values by a common divisor; effective for divisible integer sequences | +| T64 | Integer, Enum, Date, DateTime | Preprocessor (should be followed by some compression codec). Crops unused high bits; puts them into a 64x64 bit matrix; optimized for 64-bit data types | +| GCD | Integer Numbers | Preprocessor (should be followed by some compression codec). Greatest common divisor compression; divides values by a common divisor; effective for divisible integer sequences | | FPC | Floating Point Numbers | Designed for Float64; Algorithm detailed in [FPC paper](https://userweb.cs.txstate.edu/~burtscher/papers/dcc07a.pdf), [ClickHouse PR #37553](https://github.com/ClickHouse/ClickHouse/pull/37553) | | ZSTD_QAT | Any | Requires hardware support for QuickAssist Technology (QAT) hardware; provides accelerated compression tasks | | DEFLATE_QPL | Any | Requires hardware support for Intel’s QuickAssist Technology for DEFLATE compression; enhanced performance for specific hardware | -| LowCardinality | String | It's not a codec, but a datatype modifuer Reduces representation size; effective for columns with low cardinality | +| LowCardinality | String | It's not a codec, but a datatype modifier. Reduces representation size; effective for columns with low cardinality | | NONE | Non-compressable data with very high entropy, like some random string, or some AggregateFunction states | No compression at all. Can be used on the columns that can not be compressed anyway. |