Database Administrator

Lately, I met a case that the range filter predicates due to wrong cardinality issue. Let's check the following query. Recently I encountered a performance problem caused by incorrect base number caused by range filtering. Let's look at the

The portable tablespace can now be migrated across platforms, making data publishing faster and easier. In addition, external table downloads make data transfer tasks easier and faster through conversion. How do you migrate data from one database to

The network is disconnected and the DBConsole service cannot be started to solve this problem. Many Oracle 10 Gb XDJM users have encountered this problem. I have also encountered this problem in my notebook. DBConsole is usable, however, if a laptop

Oracle has five default services: 1. Service Process of OracleDBConsoleorcl oem Console 2. Service Process of OracleJobSchedulerORCL Timer 3. OracleOraDb10g_home1iSQL * Plus isql * plus service process 4. Service Process of

One customer consulted on nbu6.5 and failed to back up Oracle10g. The error code is 6. After checking the oracle log, It is shown as follows: RMAN-12001: cocould not open channel ch01RMAN-10008: cocould not create channel contextRMAN-10003: unable

Last_ SQL _Error: Error 'unknown table 'bb' on query. Default database: 'test'. Query: 'drop TABLE 'bb'/* generated B The idea is to try to stop slave, reset slave, and add bb tables (define tables as needed). Remember the bin-log and position of

When upgrading the Oracle database from 11.2.0.1.0 to 11.2.0.2.8, the software upgrade is normal, the instance upgrade is normal, and the psu is upgraded. Run @? /Rdbms/admin/catbundle psu when applying, only part of the information is displayed,

In the charging system of the Self-reconstructed data center, you need to re-design the database. How can we design the database? This is also an important course "database principles" in our own test. For those who have passed this course, we must

The field "automatic number" type changed in Access cannot be changed back! (Resolved) When the auto-increment field in access is changed to a value and then to an auto-increment field, the following message is displayed: After data is entered in

In order to reduce data redundancy during database design, it is generally designed according to the three paradigm. However, sometimes we need to obtain Fields are associated with several fields, but they are distributed in different tables. At

PostgreSQL supports arrays, but does not have a function to sort internal data elements. Today I wrote one with PLPGSQL and PLPYTHONU respectively.Example Table Structure: t_girl=# \d test_array; Table "ytt.test_array"

 1: Obtain the start time and end time of the week. Start Time of the week, starting from Monday. SQL> SELECT TRUNC (TO_DATE ('2017-11-25 10:31:11 ', 'yyyy-MM-DD HH24: MI: ss'), 'D') + 1 ASA FROM DUAL; A -----------   End Time of the week,

Continue with "golden Data configuration (4)": Click to open the link Example of the external data experiment (1) Verify the synchronization between TCUSTMER and TCUSTORD Environment: Item Source System Target System

This blog has participated in the 2014 CSDN blog contest, if you think this article is useful to you, please move a small hand to help me vote: http://vote.blog.csdn.net/Article/Details? Articleid = 32939867, thank you. For Oracle beginners and

Customize a mysql close script according to the working environment   --- 1. Save As/usr/local/mysql/scripts/mysql_env.ini # Set mysql init variablesMYSQL_USER = system # mysql UsernameMYSQL_PASS = 'Password' # mysql logon User password # Check

Reprinted please indicate the source: http://blog.csdn.net/guoyjoe/article/details/32715157   The BASE calculation method is as follows:For ASSM: 76 + (itc-1) * 24 = 52 + itc * 24For MSSM: 68 + (itc-1) * 24 = 44 + itc * 24   gyj@ZMDB> select * from

Hadoop version: Hadoop 2.2.0.2.0.6.0-0009 Well, We can do this by building Secondary Namenode, Checkpoint node or Backup node. Example: Assuming you have a Secondary Namenode. 1. Check secondary namenode checkpoint status: Dfs. namenode. secondary.

The script is updated again and shared!     #! /Bin/sh## Usage:#./Restore. sh/full path of your backup file# Ocpyang@126.com INNOBACKUPEX = innobackupexINNOBACKUPEX_PATH =/usr/bin/$ INNOBACKUPEXTMP_LOG = "/var/log/restore. $. log"MY_CNF

Redis is a single-process service. It is mainly used for memory, CPU, and disk I/O (mainly for persistence, you can consider using multiple redis instances. Before using multiple instances, we should first consider the use of CPU and memory. During

Install MySQL 5.5.35 in CentOS 6.3 By Using rpm and Source Code compiling. This article uses mysql Source Code compiling and the compiler uses Cmake. Software Release mysql-5.5.35.tar.gzand cmake-2.8.10.2.tar.gz. Please download them by yourself. 1.