Category Archives: Database

Query & DB Technic.

High CPU usage query & Adding Index

CASE: Specific query is consuming up CPU resource cause CPU Spike(100% usage) when the DB hit count is increased. Type: MSSQL 2012 In such a case, mostly the query is known, so it can be solved by creating index for this query. But in emergency status, when Application Designer is absent and when the instant response is needed by DBA… Read More »

2,484 total views, 1 views today

log truncate interruption – open transaction Case: DB Type: MS SQL 2012 DB Recovery Model: Full One day, Growing DB log size is pressing the Disk space, it almost full. See the status of db files, the log file size has been increased very big though the transaction log backup task has been taking regularly. Once to handle this situation, just trying… Read More »

2,672 total views, 2 views today

[MSSQL] Desizing the Transaction log

for further steps To desize the transaction log of statistical  database which is just for the log-likely data and of which the transaction log grows very fast, set the recovery option for that database as “SIMPLE” and truncate the log. Due to the queries to desize the logs are slightly different by the version… Read More »

8,198 total views, 10 views today

[MSSQL] CPU Usage Analysis / Queries

When usage of CPU increased in Database Server, use this query to check which is the most exhausting one.

Use below to check the detail with SPID:

2,098 total views, 1 views today

2,098 total views, 1 views today

Data Mining with Weka (5.2: Pitfalls and pratfalls)

게시일: 2013. 10. 6. Data Mining with Weka: online course from the University of Waikato Class 5 – Lesson 2: Pitfalls and pratfalls Slides (PDF): Department of Computer Science University of Waikato New Zealand 카테고리 교육 라이선스 크리에이티브 커먼즈 저작자 표시 라이선스(재사용 허용)     2,019 total views, 3 views today

2,019 total views, 3 views today

[SQL ] The Curse and Blessings of Dynamic SQL

cite from: An SQL text by Erland Sommarskog, SQL Server MVP. Latest revision: 2011-06-23. An earlier version of this article is also available in German. Translations provided by SQL Server MVP Frank Kalis. Introduction If you follow the various newsgroups on Microsoft SQL Server, you often see people asking why they can’t do: SELECT… Read More »

1,959 total views, 3 views today

[MySQL] Create Table with Auto Incremental

Example> use foodfavor; create table food (   pk1 MEDIUMINT NOT NULL AUTO_INCREMENT,   food_id char(50),   food_name CHAR(255) NOT NULL,   PRIMARY KEY (pk1) ); * reference: MyISAM Or InnoDB MySQL engine?:   2,041 total views, 3 views today

2,041 total views, 3 views today

[MySQL-ORACLE] Oracle and MySQL Compared (types and so on)

cite from: Here’s the table for comparing types of ORACLE & MySQL below: 2.2.4 Migrating Multiple Databases SQL Developer supports the migration of multiple MySQL databases if they are on the same MySQL database server. 2.2.5 Schema Migration Considerations for MySQL Schema migration considerations for MySQL apply in the following areas” Databases Mapping MySQL Global and Database-Level… Read More »

3,043 total views, 2 views today

[MySQL] Create Database-Create User-Grant on

가장 기초이면서도 종종 쓰면서도 정리해두지 않으면 매번 찾아보아야 한다. 미리 정리해둔다. –Create Database— create database simple_board; –Create User & Grant & Check Grant (for Remote Access)———– CREATE USER board_u@localhost IDENTIFIED BY ‘12345’; GRANT ALL PRIVILEGES ON simple_board.* TO board_u@localhost; SHOW GRANTS FOR board_u@localhost; –Modify Grant Privilege of User for remote access ———————————— UPDATE mysql.user SET… Read More »

2,104 total views, 3 views today

Hadoop 2.2.0 (4) – 개발환경 구축하기: Plugin 설치

하둡 설치가 끝났으면 이제 개발 해봐야죠~ 썩은 무라도 잘라야 이때까지 고생한 보람이 있겠죠?(^^;;;) 일단 Eclipse Plugin 이 존재한다는 사실은 알고 있었기 때문에 바로 검색 들어갑니다. 구글냥에서 검색해보면 이미 많은 분들의 포스팅이 있지만 검색 첫단에 나온 github 사이트의 결과를 이용하기로 합니다. (진짜.. 이런거 만들어 볼 능력이 되야 할텐데… 다음 생에?) 컴파일해도 되지만 시간을 많이 잡아먹은… Read More »

7,977 total views, 1 views today