Database Administrator

Concurrent execution of Oracle RMAN backup of a single file If a file is a file of several gigabytes or tens of thousands of megabytes, You Need To parallelize the backup of the file. Generally, one channel can only read one file, however, you can

Oracle NET configuration and working principle Oracle NET is a software layer that supports conversion between different network protocols. Different physical machines can communicate with each other through this software layer, specifically

Analysis on the storage format of Oracle nested tables Oracle nested tables are rarely used. The following describes how to store them. For example, a user corresponds to a department. SQL> select * from v $ version;BANNER----------------------------

Oracle 11g tablespace dbf File migration When the disk space of the Oracle data file is insufficient or the dbf file needs to be migrated to another location in other cases, the procedure is as follows: 1. sqlplus sys/sys as sysdba 2. shutdown

Install and test Hive based on MySQL metadata Introduction: Hive is a powerful data warehouse Query Language, similar to SQL. This article describes how to build a Hive development and testing environment. 1. What is Hive? Hive is a Hadoop-based

AWR report generation and simple analysis methodsHow to generate an AWR report: Step 1: When the database pressure test card starts: generate the first snapshot: SQL> exec dbms_workload_repository.create_snapshot (); Step 2: When the database stress

Use Oracle AMDU to extract data files from the ASM disk group Amdu-diskstring ''-extract '. ' The data file number can be obtained based on the MySQL instance query v $ asm_file view. You can also query v $ datafile. If an alias is used, you can use

Java statements for database operations are prone to errors. java statements are prone to errors. Let's first look at the following statement String sqlString = "select * from petMessage where petName = '" + pet. getPetName () + "';"; The preceding

Oracle Database experience series-Article 1 and Article 11) change the date display type of the query results in SQL developer in oracle 11g r2, that is, the setting of the session date type:Alter session set nls_date_format = 'yyyy-MM-DD HH24: MI:

ORA-21561, ORA-15055, ORA-25253 lead to DG slave database cannot apply archive, ora-21561ora-15055Yesterday I went to a customer to do inspection, by the way, to see whether the last build of the RAC-DG environment is normal, do not see do not know,

Practice: Create shell scripts for tablespace in oracle, oracleshell #! /Bin/bash # ocpyang@126.com # create tablespaceif [$ #-ne 2]; then echo "Usage: $0 TABLESPACE_NAME TABLESPACE_SIZE" exit 1fi # configure oracle env: about oracle envs, username

Hibernate implements addition, deletion, modification, and query, while hibernate implements addition and deletion. Hibernate provides rich APIs for database operations. Session is a very important class for database operations. It provides basic

[MongoDB] The high query operation of MongoDB (2), mongodboperation In the last blog, there are three query condition to be described. In the blog, we will continue to what we have leaned in the last blog.1 $ mod '$ Mod' operation is able to make us

Oracle performance analysis 6: Index scanning of data access methods, oracle Index This section describes various index scanning methods. After learning about the features of various index scanning methods, you can determine whether the scanning

Vertica "ERROR: Too many ROS containers exist", verticacontainers Original article: Vertica "ERROR: Too many ROS containers exist" Recently I encountered a problem when using Vertica. After running Vertica for a while, it always encountered the

Use left join and inner join in SQL. Left join on is a left Outer join. The data is based on the table on the left. The table data on the right is queried even if it is null, Inner join on means that the data in the tables on both sides of the left

Oracle review, oracle After I got back, I recorded several sets of videos, but I didn't know how to record them when I started recording them. If I recorded a few sets, I had nothing to do. I could record each set for dozens of minutes, in the

Operand shoshould contain 1 column (s), operandcontain This error was found during the SQL test today: Operand shoshould contain 1 column (s ). The reason is that there are multiple fields behind the in condition, and there can only be one field

PLSQL Developer can synchronize table structures and table data of different databases. The Tools Options in the PLSQL Developer menu contain the Compare User Objects and Compare Table Data functions. 1. Tools --> compare user objects This function

Wait for the event log to wait for the event solution. I insisted on reading three sets of RAC AWR every day and summarized it. Query the SQL statement of the log wait event: 9i: select * from v $ event_name where name like '% log %'; (about 14)10g: