I recently learned of some odd behavior using MySQL BETWEEN operator queries, filtering by a DATETIME column. I wrote about this over on Medium so I am sharing the post for any readers here who are interested…
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[Read more]Introduction In this article, we are going to see how a relational database executes SQL statements and prepared statements. SQL statement lifecycle The main database modules responsible for processing a SQL statement are: the Parser, the Optimizer, the Executor. A SQL statement execution looks like in the following diagram. Parser The Parser checks the SQL statement and ensures its validity. The statements are verified both syntactically (the statement keywords must be properly spelled and following the SQL language guidelines) and semantically (the referenced tables and column do exist in the database). During... Read More
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On our job schedule system. Using osc-tool cause deadlock
problem.
We investigated the root cause in detail and published this PDF
doc.
“The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood.”–John Ryan
I have interviewed John Ryan, Data Warehouse Solution Architect (Director) at UBS.
RVZ
Q1. You are an experienced Data Warehouse architect, designer and developer. What are the main lessons you have learned in your career?
John Ryan: The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood. I believe this stems from a lack of understanding of the …
[Read more]JKDB PLATFORM – our company’s data management platform
In this post, we introduce backup-restore module,focus on automatic backup and restore in a huge MySQL database environment.
Read this PDF: JKDB:BACKUP-RESTORE
“Isn’t it ironic that in 2016 a non-skilled user can find a web page from Google’s untold petabytes of data in millisecond time, but a highly trained SQL expert can’t do the same thing in a relational database one billionth the size?.–Jim Starkey.
I have interviewed Jim Starkey. A database legend, Jim’s career as an entrepreneur, architect, and innovator spans more than three decades of database history.
RVZ
Q1. In your opinion, what are the most significant advances in databases in the last few years?
Jim Starkey: I’d have to say the “atom programming model” where a database is layered on a substrate of peer-to-peer replicating distributed objects rather than disk files. The atom programming model enables scalability, redundancy, high availability, and distribution not available in traditional, disk-based database …
[Read more]Description:
I create a empty table and then alter this table's "AUTO_INCREMENT" starts from 10000000.After a long time ,MySQL lost "AUTO_INCREMENT" definition when I show this table again. MariaDB has the same problem but Percona Server is fine.
$mysql06
Warning: Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 141028725 Server version: 5.6.17-log MySQL Community Server (GPL) Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> use test; Reading table information for …[Read more]
Reprint a PDF for MySQL Injection Test
In this article, we introduce myawr and mongoawr system .
Read this PDF, you will learn how to configure them.
Recently, we create a mysql data warehouse which is based on message queue.
Most companies must prepare for particular queries in their systems if they consider to split their databases or tables into many pieces.
some problems should be solved in this situation:
1. how to get correct results in-time
2. how to build strong data warehouse for future analyst
These policies were used by YHD
They have already deployed a middle-ware layer to support these requests (between web apps and databases). Every aggregation SQL was splited into many small SQLs and runs in every data nodes.The Final result is the aggregation of these all small SQLs. In this procedure, everything was computed in memory to get high performance.
In data warehouse layer, they use self-defined ETL tools to extract data from different databases to oracle-Exadata platform. Log-based data was put into hadoop and hbase.
…[Read more]