Database Administrator

In some cases, the or condition can avoid full table scan. 1. If the where statement contains the or condition, the myisam table can use indexes, but innodb does not. 1) myisam table: Create table if not exists 'A '( 'Id' int (1) not null

-- Conventional load mode---- Load. ctl FileLoad dataInfile 'C: \ 1.txt'Into table deptFields terminated ','(Deptno, dname, loc) ---- The data is as follows:10, Sales, Virginia20, Accounting, Virginia30, Consulting, Virginia40, Finance, Virginia ----

Recent field feedback: a messaging program accessing the Oracle database records some error logs about "ORA-00060: deadlock detected while waiting for resources. However, after the communication program record is abnormal, it does not crash and can

[Root @ localhost libs] # wget http://pear.php.net/get/oci8-1.4.5.tgz[Root @ localhost libs] # tar zxvf./PDO_OCI-1.0.tgz[Root @ localhost libs] # cd PDO_OCI-1.0[Root @ localhost PDO_OCI-1.0] #/usr/local/php/bin/phpize[Root @ localhost PDO_OCI-1.0] #.

Problem: Use pl/SQL developer to debug Oracle stored procedures. Right-click the stored procedure, select test, and press f9 (debug ). If this is normal, the buttons such as run and step into can be clicked, or click run to the breakpoint, or

A cluster consists of the following three services: Shards Server: each shard is composed of one or more mongod processes used to store data.Config Server: used to store the Metadata information of a cluster, including the information of each Shard

After building the MongoDB cluster (SEE), you need to create a database, create a table, and set the partition primary key to initialize the data! (1) create a WLB database and set the table shards wlb_orders D:/mongodb-win32-i386-1.8.0/cmd> cd

The following uses PostgreSQL 9.1.2 as an example. You can also refer to the INSTALL file in the package. The procedure is as follows: 1. Download the PostgreSQL source code package, put it in any directory http://www.postgresql.org/ftp/source/v9.1.2

A bank's R & D department has purchased a new IBM HS22 blade server. It needs to install a linux system on it, remotely use Telnet and FTP services internally, and install the Oracle database.Hardware environment:IBM HS22 Blade ServerSystem software:

In MongoDB1.6, it is easy to add members to the Replica Set as follows: # Add new membersRs. add ("192.168.95.210: 10000 ");# Add new elected membersRs. addArb ("192.168.95.216: 10001 "); With this configuration, Mongo automatically synchronizes

Oracle controls the connection of ip addresses (we can also use database triggers to record user logon conditions, but cannot record users with dba permissions), simply set allowed IP addresses and prohibited IP addresses, before oracle9i, there was

The process of a Delete operation in OracleDELETE)1. Oracle reads the Block to the Buffer Cache (if the Block does not exist in the Buffer)2. record the details of the delete operation in the redo log buffer.3. Create an undo entry in the

PairMongoDBEveryone who knows about MongoDB has a headache.Global lock(Read/write lockAnd allow concurrent reads, while writing will block all reads and writes. The worst thing is that this lock is not at the table level, not at the database level,

I decided to modify the name of the database when I was idle recently. I remember I learned how to modify the name of the database by recreating the control file, you can use the nid of Oracle to modify the database name. However, this method is

As database software, mysql and Oracle are both based on standard SQL, but there are still some similarities and differences. Here we will list the differences: 1. limit (note that the row number starts from 0) Limit 4th: the first digit indicates

Install MySQL NDB Download: mysql-cluster-gpl-7.1.10-linux-x86_64-glibc23.tar.gz Before configuring the ndb, You need to systematically grasp the mysql ndb configuration method theoretically, so that you can avoid many detours.I. Pre-configuration

In Oracle databases, Oracle Auto-increment fields are not supported, but can be implemented through triggers and sequence. Assume that the [Table test] keyword segment is id and a sequence is created. The code is:[Html] Create sequence seq_test

Log on to the database using the following methods in Oracle in Linux: sqlplus/nolog conn/as sysdba, but it gets stuck at the conn/as sysdba step and cannot be logged on, and check whether the listening status does not respond. This is a bug in

I tried phpMyAdmin a few days ago. It is fully functional and easy to use. I have seen some MongoDB management tools before, so I want to give it a try. Rock_mongo has been selected, and it turns out that the selection is correct. There are also

Use mysqldump + crond for backup Create a database backup sh file such as/root/sbin/db-backup.sh DATE = 'date + % Y-% m-% d' /Usr/bin/mysqldump-uroot-p123456 mydatabase>/root/backup/mysql-backup. SQL. $ DATE Contents are all tables in the backup