ClickHouse compression test
ClickHouse supports different kinds of compressions, namely two LZ4 and ZSTD. But in short, LZ4 is fast but provides smaller compression ratio comparing to ZSTD. While ZSTD is slower than… Read more »
How to backup and restore your Clickhouse Database
ClickHouse is known as a data analytics processing engine. ClickHouse is one of the open-source column-oriented database-oriented management systems capable of real-time generation of analytical data reports using SQL queries…. Read more »
How To Install and Configure an Apache ZooKeeper Single/Cluster on Ubuntu 20.04
Introduction Apache ZooKeeper is open-source software that enables resilient and highly reliable distributed coordination. It is commonly used in distributed systems to manage configuration information, naming services, distributed synchronization, quorum,… Read more »
How to configure Clickhouse in sharding and replication cluster
Introduction Clickhouse is a column store database developed by Yandex used for data analytics. In this article I will talk about setting up a distributed fault tolerant Clickhouse cluster. If… Read more »
How To Install and Use ClickHouse on Ubuntu 20.04
Introduction ClickHouse is an open source, column-oriented (like MariaDB Columnstore) analytics database created by Yandex for OLAP and big data use cases. ClickHouse’s support for real-time query processing makes it… Read more »
Oracle 20c : Database In-Memory Base Level included on Enterprise Edition
Database In-Memory is an option to Enterprise Edition. Database In-Memory now has a new “Base Level” feature. This allows the use of In-Memory with up to a 16GB column store… Read more »
A LOT OF FALSE ‘Global Cache Blocks Lost’ ALERTS REPORTED BY ENTERPRISE MANAGER CLOUD CONTROL 13C RELEASE 4
SYMPTOMS The alert message looks like EM Event: Warning:TEST_PDB1 – Total global cache block lost is 15. Host=db-test01.local Target type=Database Instance Target name=TEST_PDB1 Categories=Error Message=Total global cache block lost is… Read more »
Oracle Autonomous Database: Dedicated vs Serverless
This post describes the 5 main differences between ATP-D & ATP-S and the 5 main ATP-D physical characteristics and constraints. Autonomous Transaction Processing Dedicated (ATP-D) is a deployment choice that… Read more »
Delete unmapped multipath drive: couldn’t get target port group
When we go to delete a lun that is no longer mapped, we may get this error sdXX: couldn’t get asymmetric access stateAfter unmapping the LUN from the SAN storage… Read more »
Apache 2.4 Web Server Hardening and Security Guide
The Web Server is a crucial part of web-based applications. Apache Web Server is often placed at the edge of the network hence it becomes one of the most vulnerable… Read more »