Database Administrator

Oracle functions (search character positions in strings (full-width Calculation of 1 character )) INSTR (C1, C2 [, I [, J]) [Function] searches for a specified character in a string and returns the location where the specified character is found;

1. The insert format is. /** * Write a time Method */ Public staticStringgetStringDate (){ Date d = new Date (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyy-MM-dd "); Return sdf. format (d ); } Insert: Art. setArtAddTime (java. SQL. Date.

I. Resource requirements:At least 1024 MB physical memory1024-2048 requires 1.5 times of interactive space2048-8192 requires 1 time of interaction space8192-requires 0.75 times of interaction spaceAt least 400 MB/tmp temporary directory SpaceOracle

1. query and modify the undo_retention parameter: Run the show parameter undo command to view the current database parameter undo_retention settings. Shown as follows: Undo_management string AUTOUndo_retention integer 10800Undo_suppress_errors

After MySQL is compiled and installed, it cannot be started properly. Example: Prompt 'can't connect to local MySQL server through socket '/tmp/MySQL. sock' I have read that this file does not exist, but if MySQL is started properly, it should be

The syntax of the SELECT... for update statement is as follows:SELECT... for update [OF column_list] [WAIT n | NOWAIT] [skip locked];Where:The OF clause is used to specify the columns to be updated, that is, to lock specific columns on the row.The

By default, after PHPMyAdmin is installed, the information_schema database is displayed no matter what account you use to log on to the database. However, you cannot perform operations on the database. You can only view the database, this database

First, you need to repeat the related concepts. Functions in Oracle databases can only be called by others. stored procedures can be executed separately and stored procedures can be called, the role package can place any statement (process, function,

Error message: Starting MySQL. Manager of pid-file quit without updating file. [FAILED]Vim install_mysql.shCHOST = "x86_64-pc-linux-gnu"CFLAGS = "-march = nocona-O2-pipe"CXXFLAGS = "$ {CFLAGS }"./Configure \"-- Prefix =/usr/local/mysql "\"--

Execute the following method immediately, and pass the current variable in with USING. EXECUTE IMMEDIATE'Begin'Work_Order_Req_Line_Util_API.Create_Po_Allowed (: requisition _,: line_no _,: release_no _);END ;'USING requisition_no _, line_no _,

Hibernate tuning is not just about setting lazy, but about who maintains this field. This time we want to optimize the query statement -- select new map (). Description of the select new map statement. Statement 1: String hql = "select s. name from

After upgrading mysql from mysql 5.1 to 5.5 in Linux, it is found that the stored procedure is unavailable. When you create and use a stored procedure, The system prompts "Cannot load from mysql. proc. The table is probably updated upted. I checked

1. InstallDownload the compiled installation package or pre-compiled installation package. Here, use the pre-compiled version. [@ S1.yejr.com ~] # Tar zxf mysql-proxy-0.6.0-linux-rhas4-x86.tar.gz [@ S1.yejr.com ~] # Cd

Operating Environment: CentOS 6.4 64-bit First, create the/ibddir directory and modify the owner of the/ibddir directory and the corresponding group: chown-R mysql: mysql/ibddir Operation 1: Create table 'd _ TF_DATA_AGGREGATION_MYISAM '( 'Strative _

Configure Oracle lsnrctl and auto start 1. Set Host Name [Root @ www ~] # Cat/etc/sysconfig/networkNETWORKING = yesHOSTNAME = www.bkjia.com 2. Set the Host Name and IP address [Root @ www ~] # Cat/etc/hosts127.0.0.1 localhost. localdomain localhost4

Environment variable Oracle_UNQNAME not defined. Please set ORACLE_UNQNAME to database unique name. In fact, it is the problem of em to reconfigure emca. Pay attention to setting ORACLE_UNQNAME before. Summary: 1. Modify the DBSNMP password: To

The experiment is divided into two steps:1. LMT local management of tablespaces, ASSM automatic segment management when the data file structure analysis Oracle 11G: 0 operating system block, 1-2 is the file header, 3-127 is the bitmap information.

After the data files in the UNDO tablespace are deleted by mistake: Back up the database before the operation to avoid greater losses.Ideas:1. Remove the accidentally deleted data file offline2. Create an UNDO tablespace and data file after the

When you look at the histogram of a field, you cannot see the values of high and low values. You need to convert the values as follows. SQL> SELECT column_name,Num_distinct n_d,Low_value o_low_value,Display_raw (low_value, data_type)

After establishing RAC on a virtual machine a few days ago, I tried to test the two functions of Oracle TAF (transparent application failover) and Server Load balancer. 1. Server Load balancer First, edit the tnsnames. ora file on the server and