Database Administrator

PostgreSQL MVCC source code implementation MVCC is no stranger to every DBA, that is, Multi-Version-Control ). Because the data has multiple versions, the read and write operations are separated to a certain extent, improving the database's ability

How to configure the STATSPACK performance report of Oracle 11g ADG Create a normal STATSPACK report user on the master database Sqlplus/as sysdba SQL> @? /Rdbms/admin/spcreate. SQLSQL> -- cancel some settings of $ Oracle_HOME/sqlplus/glogin.

Create the wm_concat function on Oracle 12C The wm_concat function has been abandoned on Oracle 11gR2 and 12C. At that time, many of our programmers used this function in the program, leading to program errors. To reduce the workload of programmers

PostgreSQL physical file ing We know that in PG, each relation, that is, the table, has several fork mappings. "MAIN" fork is used to store the data in the master table, "FSM" fork is used to manage the free space, and "visibility" fork is used to

MySQL index and Query Optimization Index type: Common indexes are the most basic index types and have no restrictions such as uniqueness. The unique index is basically the same as the normal index, but all index column values are unique. The primary

Simulation of rm-rf *. dbf recovery in cold backup Backup recovery has always been a major concern for all relational databases. The following describes the Cold Standby database, simulates and destroys data files to restore the database, and

Record Oracle bad block Repair Process The following error was reported during RMAN cold backup yesterday when I received a backup call from my colleague. A tablespace backup failed.RMAN-00571: ========================================================

/* + SYS_DL_CURSOR */This hint, sys_dl_cursorhint Run the/* + SYS_DL_CURSOR */hint. Today in a db SQL statement, encountered this/* + SYS_DL_CURSOR */hint, after baidu, In the post of Huang Wei http://www.hellodba.com/reader.php? ID = 201It is

12-SQLite transactions and 12-sqlite transactionsI. Transaction Overview A transaction is a series of operations performed as a single logical unit. Multiple operations are submitted to the system as a whole, either executed or not executed.

ADO. NET -- Connection, Command ., Ado. netconnection The. NET Framework Data Provider includes four core objects: Connection, Command, DataReader, and DataAdapter. Here, I will just talk about the objects that are frequently used in SQL Server. The

[Translated from mos] in Oracle db 12c, The alert_sid.log permission is changed every time the log is switched. 12calert_sid.log In 12c, The alert_sid.log permission is changed each time the log is switched. Source:Alert log file's permissions

Data structure, data structure and AlgorithmStack chain Storage 1. chained representation of stackThe stack's chain storage structure is called the chain stack, which is a single-chain table with limited operations. The insert and delete operations

(18) partitions in mysql (after development), 18 mysql Overview Before getting started, I saw the partition, And I squeezed it. Yesterday, I finally learned what partitioning is, but that is also the case. Today, we can sum up that good memory is

Common commands for create table and Common commands for table Create table students (stuID integer not null, stuname char (30) not null, sex int not null); create table students (stuID integer not null, stuname char (30) not null, sex int not null,

[LeetCode] Department Highest Salary, solution report, leetcodesalary Question The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id. Id Name Salary

Error 1313: RETURN is only allowed in a function SQL Statement, 1313 allowed 1. Error description 14: 07: 26 Apply changes to rand_stringError 1313: RETURN is only allowed in a function SQL Statement: CREATE PROCEDURE 'rand _ string' (n int)

Oracle11gR2 reports TNS-01190 in Windows 7: The user is not authorized to execute the requested listener comm, authorized In Windows 7, enter the Oracle listener named "lsnrctl" in the CMD console and execute related listening commands, as shown in

The item set based on the node list indicates the latest progress of the framework's frequent item set mining and the latest progress of the framework.The latest paper was published in Expert Systems with Applications 2015, volume 42, Issue 13.This

ORA-03113: end-of-file on communication channel, filechannel Oracle open error: SQL> alter database open2; Alter database open * ERROR at line 1: ORA-03113: end-of-file on communication channel Process ID: 29196 The Session ID is 1144 Serial

Redis learning records and redis recordsRedis is a key-value storage system. Similar to Memcached, Memcached supports more storage value types, including string, list, set, and zset) and hash (hash type ). These data types support push/pop,