Database Administrator

The naming method for Pg XLOG files (REDOLOG) names is defined in the XLogFileName macro, the time series ID, log ID, and segment ID are composed of eight hexadecimal numbers. For example, 000000000000000000008f. # Define XLogFileName(Fname, tli,

1. Set the storage location of the backup file, and automatically backup the control file during Backup C: \ Documents ents and Settings \ wwang> rman target/-- backup on the target database Recovery MANAGER: Release 11.2.0.1.0-Production on Monday

Oracle has many parameter files, but the most important one is database parameter files. Database parameter files include pfile and spfile. Pfile must be manually modified. It is a text file, and spfile is a binary file, which can be changed

In Oracle Data Guard, the Redo Gap is generated because of some network or other problems, resulting in the interruption of the redo transmission. After the fault is eliminated, these redo files that have not been transferred will be discovered by

To set latency Apply, you need to use "DELAY =" on the log_archive_dest_n parameter. For example, DELAY = 360 (in minutes) indicates that the latency is 360 minutes (6 hours ). For example:SQL> alter system set log_archive_dest_2 = 'service =

Recently, I have dealt with some Oracle character data types. I want to learn from them as follows: 1. First, compare the char and varchar2 types: Differences: 1. the length of CHAR is fixed, while the length of VARCHAR2 can be changed. For example,

I. Environment Introduction Data Guard environment: Primary Database: Oracle10.2.0.5.0OS: RedHat 4.4Host Name: sourceIP Address: 192.168.10.101Database SID: sourceDB_UNIQUE_NAME: source_pr Standby Database: oracle10.2.0.5.0OS: redhat 4.4Host Name:

In the previous topic, we have actually made a complete introduction to the backup and recovery of rman. We talked about the backup of databases, tablespaces, parameter files, and control files, at the same time, we also talked about their recovery,

By default, mysql compilation and installation may fail to connect to mysq server after installation, and an error is reported. "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysql. sock' (2 )" This will cause a

Database dirty reads, non-repeated reads, and Phantom reads are all related to the isolation of transactions. First, let's take a look at the four features of transactions.Four major features of transactions (ACID ): Atomicity: a transaction is

Today, we can see the following problems in the daily response of data centers A and B: Renewal point 1 day: Tue Jul 31 03:02:50 2012 Errors in file/soft/Oracle/diag/rdbms/a1qzdb/a1qzdb1/trace/a1qzdb1_ora_5374100.trc: ORA-00245: control file backup

Both Oracle and mysql databases provide powerful date formatting formats. This article compares the formatting characters of the two databases for your reference: Common Format String Mysql: DATE_FORMAT (now (), '% Y-% m-% d % H: % I: % s

The HW lock is provided to prevent multiple processes from simultaneously modifying HWM. The process to move HWM must obtain the HW lock. If a contention occurs during the acquisition of the HW lock, the system waits for the enq: HW-contention event.

Currently, no database product is dedicated to cross-IDC optimization. Theoretically, the best solution adopted by the industry is based on the Paxos protocol (currently only implemented by google, google f1), today we only discuss considerations

1. Environment Description:Original machine: 192.168.102.156 Oracle 10.2.0.1Target: 192.168.102.157 ORACLE 10.2.0.12. Create a table for the database.SQL> create table rmantest (id number (9 ));Table created.SQL> insert into rmantest (id) values (88

1. display the current configuration information======================================1.01 RMAN> show all;1.02 check non-default values in RMAN settings:SQL> select name, value from v $ rman_configure; -- before 11gSQL> SELECT CONF #, NAME, VALUE

There are two methods: one is to transfer controlfile out and modify the database name and then recreate it; the other is to use the nib tool to modify it. Here we will introduce how to modify the nib tool. The tool nib is provided by Oracle 9i and

If an error occurs when Renaming an Oracle table: you are not allowed to rename this table, try to drop the materialized view log on the table. SQL> create materialized view log on test_1; The materialized view log has been created. SQL> alter

RMAN-04015 error reported when rman cannot be enabled after manual Oracle database creation The solution is as follows:SQL> shutdown immediate;SQL> startup upgrade;SQL> @? /Rdbms/admin/utlirp. SQLSQL> @? /Rdbms/admin/utlrp. SQLSQL> shutdown

Mongodb databases are also inseparable from necessary maintenance, such as backup, recovery, import, and export. In fact, backup and recovery are easier to import and export than normal, so most of the time you can use backup and recovery