Capacity-On-Demand You can reduce the number of active cores on your Exadata database servers to lower the initial software licensing cost, but this does not change the hardware cost.
MySQL 8.0 Study 005 Tips
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OCI SSH Key Tips
Introduction The SSH (Secure Shell) protocol is a method for secure remote login from one computer to another. SSH enables secure system administration and file transfers over insecure networks using encryption to secure the connections between endpoints. SSH keys are an important part of securely accessing Oracle Cloud Infrastructure compute instances in the cloud.
If you already have an SSH key pair, you may use that to connect to your environment. We recommend you use the Oracle Cloud Shell to interface with the OCI compute instance you will create. Oracle Cloud Shell is browser-based, does not require installation or configuration of anything on your laptop, and works independently of your network setup. However, if you prefer to connect via your laptop, please select an option based on your configuration.
Option 1: Oracle Cloud Shell
Option 2: MacOS
Option 3: Windows 10
Option 4: Prior Windows Versions
Option 5: SSH Keys for Linux
ssh-keygen
参考:
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2022年最后一个工作日,学习下MySQL8.0
用Tpcc-mysql测试下最新版本MySQL8.0.32
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MySQL dbdeployer tool Tips
DBdeployer is a tool that deploys MySQL database servers easily. This is a port of MySQL-Sandbox, originally written in Perl, and re-designed from the ground up in Go.
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MySQL Functional Index Tips
Database indexes are used to help query performance. Database indexes typically contain information about data in a specific column of the database table. With the introduction of functional indexes in MySQL 8.0.13, we can now create indexes based on the result of an expression or function.
The Rules Functional indexes can increase query performance without having to rewrite the query to address any bottlenecks. However, there are some rules that we need to follow.
Expressions MUST be contained in parentheses to differentiate them from columns.
INDEX((col1 + col2)) vs INDEX( col1, col2)
We can create an index that has functional and non-functional definitions.
INDEX((col1 + col2), col1)
Functional index definitions cannot contain only column names.
INDEX ((col1), (col2)) will throw an error.
Functional index definitions are not allowed in foreign key columns.
The index will only be used when a query uses the same expression.
select count(*) from test_data where col1 - col2 = 0 will NOT use the index we created.
We would need to create a new index using the expression (col1-col2).