diff --git a/ReadMe.md b/ReadMe.md index 9f119539..4216cd29 100644 --- a/ReadMe.md +++ b/ReadMe.md @@ -68,6 +68,13 @@ Build from the sources: GO111MODULE=on go get github.com/Altinity/clickhouse-backup/cmd/clickhouse-backup ``` +## Brief description how clickhouse-backup works + +Data files is immutable in `clickhouse-server`. +During backup operation `clickhouse-backup` create file system hard-links to exists `clickhouse-server` data parts via executing `ALTER TABLE ... FREZZE` query. +During restore operation `clickhouse-backup` copy hard-links to `detached` folder and execute `ALTER TABLE ... ATTACH PART` query for each data part and each table in backup. +More detailed description available here https://www.youtube.com/watch?v=megsNh9Q-dw + ## Common CLI Usage ### CLI command - tables