Database Administrator

How to control the access of common users to pdb information in cdb Purpose:Study the permissions required for common users to switch between different PDBs;Study how to restrict a common user to access only information corresponding to a certain

MySQL backup script based on Innobackupex Innobackupex is part of Xtrabackup, and its essence is to call xtrabackup. The main difference is that Xtrabackup not only supports the innodb engine, but also supports the xtradb engine. This article mainly

Oracle index (notes) 1. Oracle index null When a single column index is created on an empty value column, if the search condition is null, it can be seen in the interpretation plan that oracle does not use index query for this column; However, when

Connect to the Oracle database without installing the Oracle client in Linux Connect to the Oracle database without installing the Oracle client in Linux 1. mkdir-p/opt/oracle2. cd/opt/oracle3. Go to the oracle official website to download the

Cannot open shared object file error handling when logging on to OGG 1. ErrorOn the Linux server, the newly installed goldengate (OGG) is used. /ggsci log on to the console and report. /ggsci: error while loading shared libraries: libnnz11.so:

Oracle 11.2.0.4 the time when RAC logs are recorded is inconsistent with the operating system time. After Oracle 11.2.0.4 RAC is set up and the time zone is changed at the system level, it is found that the RAC log records are inconsistent with the

SQL import txt and SQL time format operations Load data local infile "path name" into table "table name" For example, if the specific location of my file is "f: \ dataset \ beijing \ xx.txt" and the name of the created table is "person", the

ORA-00600 kcratr_nab_less_than_odr In the morning, the Oracle database reported the following error: Successful mount of redo thread 1, with mount id 339694234Database mounted in Exclusive ModeLost write protection disabledCompleted: ALTER DATABASE

Oracle Character Set modification (ORA-29275) Today, a friend of the database ORA-29275 part of the multi-byte characters, the corresponding field can only use to_char to query the normal, it is a character set problem. You have modified the

Install MySQL5.5 (single instance) in the source code of CentOS) 1. Media preparation Note: Due to the CMAKE Method Used for MySQL5.5 source code compilation, download the cmake installation package and the MySQL5.5 installation package in

Use Rails in Ubuntu 14.04 to connect to the MySQL database Rails comes with sqlite3 in all aspects, but the free version lacks a fatal function: Add a password! Although the third party has a compiled binary version of the encrypted version, let's

Oracle 11g cluster troubleshooting Symptom:The Oracle cluster does not seem to be drifting IP addresses. The number of all session connections is only concentrated on one node. If this node is disconnected, it will not be automatically connected to

ORA-01461 error resolution, ora-01461 ErrorORA-01461 troubleshootingORA-01461: can bind a LONG value only for insert into a LONG columnThe connection pool of weblogic is used, and there is no problem.Switch to tomcat or direct jdbc call, and an

Create tens of millions of test tables and mysql database test tables in the mysql databasePreface: I have recently prepared to learn more about mysql, including the features, performance optimization, and database sharding of various engines. To

PL/SQL Developer sets automatic transaction submission, pldeveloper Previously, the update table was used on a test machine. There was no commit or PL/SQL Developer. The next day, I checked the table on my computer and found that the record was

Step by step, gathering small streams ------ SQL operations on database tables, ------ SQL I remember that at the beginning, database operations were limited to adding, deleting, modifying, and querying data. However, as the number of applications

Argument-difference between select count (*) and select count (1),-selectcount Preface: Today, I saw a blog reposted by my colleague titled "The difference between select count (*) and select count (1)", which is due to interest, just like verifying

MySQL MHA introduction and its advantages MHA is the best choice for many enterprises that use MySQL databases for high availability. It is easy to use and powerful, and implements automatic master-slave failover Based on the MySQL replication

Mysql storage engine Introduction # Not easy to write The default INNODB engine is used after ORACLE is acquired. MyISAM Default storage engine before Mysql5.5.5 Supports large files, usually 256 TB Suitable for read-write-less

Oracle trunc () function usage-2, oracletrunc2. TRUNC (for number)The TRUNC function returns the processed value. Its working mechanism is very similar to that of the ROUND function, except that the function does not ROUND or select the part before