diff --git a/docs/about-us/history.md b/docs/about-us/history.md index 6c9659d547b..c6d38917dc2 100644 --- a/docs/about-us/history.md +++ b/docs/about-us/history.md @@ -19,7 +19,10 @@ As of April 2014, Yandex.Metrica was tracking about 12 billion events (page view ## Usage in Yandex.Metrica and other Yandex services {#usage-in-yandex-metrica-and-other-yandex-services} ClickHouse serves multiple purposes in Yandex.Metrica. -Its main task is to build reports in online mode using non-aggregated data. It uses a cluster of 374 servers, which store over 20.3 trillion rows in the database. The volume of compressed data is about 2 PB, without accounting for duplicates and replicas. The volume of uncompressed data (in TSV format) would be approximately 17 PB. +Its main task is to build reports in online mode using non-aggregated data. +It uses a cluster of 374 servers, which store over 20.3 trillion rows in the database. +The volume of compressed data is about 2 PB, without accounting for duplicates and replicas. +The volume of uncompressed data (in TSV format) would be approximately 17 PB. ClickHouse also plays a key role in the following processes: @@ -29,13 +32,13 @@ ClickHouse also plays a key role in the following processes: - Running queries for debugging the Yandex.Metrica engine. - Analyzing logs from the API and the user interface. -Nowadays, there are a multiple dozen ClickHouse installations in other Yandex services and departments: search verticals, e-commerce, advertisement, business analytics, mobile development, personal services, and others. +Nowadays, there are multiple dozen ClickHouse installations in other Yandex services and departments: search verticals, e-commerce, advertisement, business analytics, mobile development, personal services, and others. ## Aggregated and non-aggregated data {#aggregated-and-non-aggregated-data} There is a widespread opinion that to calculate statistics effectively, you must aggregate data since this reduces the volume of data. -However data aggregation comes with a lot of limitations: +However, data aggregation comes with a lot of limitations: - You must have a pre-defined list of required reports. - The user can't make custom reports.