The telecommunications industry is experiencing unprecedented growth and transformation, driven by technological advancements, increasing customer demands, and evolving market dynamics. To stay relevant and competitive in this rapidly changing landscape, Telcos need to harness the power of real-time analytics. Real-time analytics provides Telcos with timely and actionable insights that empower them to make informed decisions, […]
In previous article we talked about migrating from OLTP databases to the ClickHouse database. This migration technology tool will soon be available in the ChistaDATA DBaaS and you can enjoy the advantages of ClickHouse database with only a single click. Today we’ll start by showing you how to migrate from an Oracle database to Kafka, […]
Role-based access control (RBAC) is a method of restricting access to a resource based on the roles of the users within an organization. RBAC can ensure that the users are allowed to access the resource and the information within the scope of their job and nothing more or less. RBAC is based on the roles […]
Picture Courtesy – Photo by Mariana Kurnyk Sharding is a process in which a large database table is divided horizontally into smaller ones (with same schema/columns) and stored across different nodes. ClickHouse supports sharding via distributed table engine. You can learn more about sharding and distributed engines in this blog post. While sharding is a […]
Space management and direct path load are important considerations in ClickHouse for optimizing storage efficiency and data loading performance. Here are some tips and tricks for space management and direct path load in ClickHouse: Space Management: Direct Path Load: By employing these tips and tricks for space management and direct path load in ClickHouse, you […]
In ClickHouse, evaluating the accuracy of cardinality estimates in a query plan can be challenging since ClickHouse relies on different heuristics and sampling techniques to estimate cardinalities. However, you can take the following steps to gain insights into the accuracy of cardinality estimates: It’s important to note that ClickHouse’s cardinality estimation is not always exact […]
To drop an existing histogram on a ClickHouse column and prevent the Auto Stats gathering job from creating it in the future, you can follow these steps: For example: DESCRIBE TABLE your_table; Identify the column name that has the histogram. ALTER TABLE your_table MODIFY COLUMN your_column CLEAR HISTOGRAM; Replace your_table with the name of your […]
To display and read the execution plans for a SQL statement in ClickHouse, you can follow these steps using real-life data sets: For this example, we’ll use a simple SELECT statement to retrieve data from the orders table: SELECT customer_id, COUNT(*) AS order_countFROM ordersGROUP BY customer_idORDER BY order_count DESC; This query will calculate the number […]
Grouping, rollup, and cube are SQL query operations that allow for grouping and aggregation of data based on multiple dimensions or attributes. In ClickHouse, these operations are implemented using the GROUP BY clause, which allows you to group data based on one or more columns. Here are some real-life data examples to illustrate how to […]
Derived tables are tables that are created on-the-fly as a result of a query. They are temporary tables that exist only for the duration of the query, and are not stored in the database. ClickHouse supports derived tables as a way to simplify complex queries and reduce the amount of data that needs to be […]