Configuration steps for mysql dual-machine hot standby and mysql dual-machine hot standby Set dual-machine Hot Standby: First, you must create a synchronization user on the two machines: Grant replication slave on *. * to 'repdcs '@ '192. 168.21.39'
Mysql master-slave configuration parameters and stepsMaster-slave configuration steps:Create the database to be synchronized in the master database, create the account of the master database, and modify the configuration of the master and slave
SegmentFault! 1024 programmer game "Red shore call" task introduction the next day, segmentfault Seeing that the lab is about to close, let's take a look at the problem solving process (in fact, everyone is waiting for the third question to come
What is a tablespace? 1. view the tablespace and datafile corresponding to a userSelect t1.username, t2.tablespace _ name, t2.file _ name, t1.temporary _ tablespace, t3.file _ nameFrom dba_users t1Left joinDba_data_files t2On t1.default _ tablespace
SQL for xml query sample, xmlsample Sample 1: declare @x xml select @x=' EveryMonday 2000-01-01T19:30:00 EveryThursday 2000-01-01T19:30:00 EverySunday 2000-01-01T19:30:00 'SELECT
Tablespace (bottom), tablespace ( 7. Table space size -- View the table space usageSelect a. tablespace_name,Round (a. bytes/1024/1024) "Sum MB ",Round (a. bytes-B. bytes)/1024/1024) "used MB ",Round (B. bytes/1024/1024) "free MB ",Round (a. bytes-B.
The usage of Aggregate functions count, max, min, sum, avg, and NVL in oracle,Usage of Aggregate functions count, max, min, sum, avg, and NVL in oracle The grouping function aggregate function performs computation on a column in a group of rows and
[Mysql] Mysql database processes Chinese characters transmitted in Servlet, mysqlservlet The default encoding of many Mysql instances is latin1. If Mysql does not change the encoding during installation, it cannot be entered into Chinese directly
Tablespace (upper), tablespace ( 4. directly modify the tablespace resizing:(1) General tablespace:Automatic Scaling: alter database datafile '/oracle/app/oradata/tbs_sys_ptcl.dbf' autoextend on;Disable auto Scaling: alter database datafile '/oracle/
Specific operation commands for adding and deleting new users in mysql, and specific operations in mysqlMethod 1: Use the mysql root (root permission) user to log on and directly grant permissions to users. You can also create
Hibernate Tool slf4j error, hibernateslf4j After the Hibernate Tool 3.4 plug-in is installed in eclipse, MySql console and model are generated, and slf4j errors are generated all the time, leading to the inability to continue. The solution is as
Configure hugepage and linuxhugepage in Linux For Oracle database servers with large memory, it is necessary to configure HugePage. The following describes how to configure Huge: My environment: OS: CentOS release 6.4 (Final) Oracle: 18.104.22.168 RAC1.
Silent index hint: hint is manually allocated to the hash area, which does not result in 5 hours. After optimization, the hint is 20 minutes. My colleague sent a statement saying that the result could not be returned within five hours. I am so
TNS-01251: Cannot set trace/log directory under ADR, tns-01251adr 11204 RAC environment error TNS-01251: Cannot set trace/log directory under ADR LSNRCTL> set current_listener listenerCurrent Listener is listenerLSNRCTL> set current_listener
Common Oracle Database classic queries and oracle database queries This document collects common database queries and requires the database administrator privilege: 1. query temporary tablespace usage SELECT TABLESPACE_NAME, TABLESPACE_SIZE / 10
Oracle histogram, Histogram Histogram when the data distribution of a column is uneven, in order to allow CBO to generate the best execution plan, we may need to collect a histogram for the table. The maximum number of buckets in the histogram is 254
OR leads to Cartesian product, or Cartesian Recently, I monitored the database and found that the following statement ran very slowly. The original execution plan went through, resulting in Cartesian Product. Let's look at the following
Accidental deletion of stored procedures, accidental deletion of file restoration Software After the stored procedure is deleted by mistake, use the following statement to locate the deleted stored procedure and restore it. You need to log on with
Two-step commit of the MongoDB operation manual CRUD transaction, mongodbcrudPerform Two-Step submissionOverview This section provides a multi-record update or multi-record transaction template that uses two-step commit to complete multi-record
Rman (I), rman (CHANGE command to CHANGE the backup and copy status1. change backupset 100 unavailable The CATALOG command is used to add backup fragments and copies to the RMAN database.1. Add the data file copy information to the RMAN