From be47ad325e80679eaf1045144b72534e5ec777c4 Mon Sep 17 00:00:00 2001 From: Anna Date: Thu, 11 Mar 2021 13:06:32 +0300 Subject: [PATCH] update --- docs/en/engines/database-engines/atomic.md | 24 +++++++++------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/docs/en/engines/database-engines/atomic.md b/docs/en/engines/database-engines/atomic.md index 52e4ed4cee5..05698bc4f16 100644 --- a/docs/en/engines/database-engines/atomic.md +++ b/docs/en/engines/database-engines/atomic.md @@ -8,26 +8,21 @@ toc_title: Atomic - What the Database/Table engine does. - Relations with other engines if they exist. +All tables in DatabaseAtomic have persistent UUID and store data in `/clickhouse_path/store/xxx/xxxyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy/` where `xxxyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy` is UUID of the table. +RENAMEs are performed without changing UUID and moving table data. +Tables in Atomic databases can be accessed by UUID through DatabaseCatalog. +On DROP TABLE no data is removed, DatabaseAtomic just marks table as dropped by moving metadata to /clickhouse_path/metadata_dropped/ and notifies DatabaseCatalog. +Running queries still may use dropped table. Table will be actually removed when it's not in use. +Allows to execute RENAME and DROP without IStorage-level RWLocks + ## Creating a Database {#creating-a-database} ``` sql CREATE DATABASE ... ``` -or - -## Creating a Table {#creating-a-table} -``` sql - CREATE TABLE ... -``` **Engine Parameters** -**Query Clauses** (for Table engines only) - -## Virtual columns {#virtual-columns} (for Table engines only) - -List and virtual columns with description, if they exist. - -## Data Types Support {#data_types-support} (for Database engines only) +## Data Types Support {#data_types-support} | EngineName | ClickHouse | |-----------------------|------------------------------------| @@ -63,4 +58,5 @@ Result: Follow up with any text to clarify the example. -[Original article](https://clickhouse.tech/docs/en/database_engines/atomic/) + +[Original article](https://clickhouse.tech/docs/en/database-engines/atomic/)