Tag:data file

  • Storage structure of Oracle Database


    The storage structure of Oracle is divided into physical storage structure and logical storage structure. 1、 Physical storage structure: refers to the files existing on the hard disk Data file A database can be composed of multiple data files, which really store database data. A data file is an operating system file. The objects (tables […]

  • Handling of ora-01111, ora-01110, ora-01157


    abnormal Recovery fails when a delay is found in DG synchronization from the database. The background log will report the following exception: Solve According to the source address and local data file storage path, the collation statements are as follows: `alter system set STANDBY_FILE_MANAGEMENT=’MANUAL’ scope=both;` `alter database rename file ‘/data/app/oracle/product/11.2.0/dbhome_1/dbs/UNNAMED00243’ to ‘/data/app/oracle/oradata/PSPROD/PSPRODDG/datafile/o1_mf_gpapp_h4dnw6m6_.dbf’` The error is […]

  • Basic concepts of SQL Server database, table and data type


    1、 Data storage structure of SQL Server SQL server is a database management system, which needs to store high-capacity data in an effective way. To better understand how SQL server processes data, you need to understand the storage structure of the data. 1. File type The database is stored in files on disk, which consists […]

  • Installing Oracle database (alicloud source) with docker under virtual machine


    Environmental preparation Docker environment Install Docker Create a new virtual machine without installing the docker environment. Execute the following command to install it:yum install docker -yyum updateUpgrade everything that can be upgraded on the machine to the latest version~After installationdocker –versionTo view the installed version of dockerDocker version 1.13.1, build cccb291/1.13.1 Start Docker rootUser execute […]

  • Hadoop series (II) maxtemperature


    The sample code of Hadoop authoritative guide (Third Edition) can be found here. Please refer to the steps in readme for compilation. The maxtemperaturemapper code is as follows: package com.nasuf.maxtemperature; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Mapper; import java.io.IOException; public class MaxTemperatureMapper extends Mapper<LongWritable, Text, Text, IntWritable> { private static final int MISSING = […]

  • Kafka file storage mechanism


    1、 Storage file structure topic: can be understood as the name of a message queue partitionTo achieve scalability, a very large topic can be distributed to multiple brokers (i.e. servers), and a topic can be divided into multiple partitions, each of which is an orderly queue segment: partition is physically composed of multiple segments message: […]

  • Principle of cold and hot separation technology for decryption cloud HBase


    Preface HBase is a popular distributed database for mass data storage. Mass data storage often involves a cost problem, how to reduce the cost. The common solution is to manage data through cold and hot separation. Cold data can use higher compression ratio algorithm (zstd), lower replica coding algorithm, and cheaper storage device (HDD, high […]

  • Oracle error reporting ora-01653: table XX cannot be extended through 8192 (in table space XX? Data)


    1 problem Insert data into the Oracle 10g database in batches. When nearly 200 million pieces of data are inserted, the following error is reported:Ora-01653: table XX cannot be extended by 8192 (in tablespace XX? Data). Looking at the table space, it is found that the size of the table space has reached 32g, but […]

  • Virtual machine simulates Oracle RMAN backup and several recovery scenarios


    1、 Oracle tablespace, test table, user environment preparation Create bocotest tablespacecreate tablespace bocotest logging datafile ‘/opt/ora_data/bocotest_01.dbf’ size 1G; create user lijian identified by lijian default tablespace bocotest; grant dba to lijian; grant create session to lijian; grant unlimited tablespace to lijian; grant create table,create view,create trigger, create sequence,create procedure,create type to lijian; In this table […]

  • Solutions to insufficient space of sysaux in Oracle Database


    First, check the usage of sysaux tablespace SELECT tbs SYSAUX, Sum (totalm) total size m, Sum (usedm) used space m, Sum (retained m) the remaining space m, Sum (usedm) / sum (totalm) * 100% used, Sum (remainedm) / sum (totalm) * 100% remaining FROM ( SELECT b.file_id ID, b.tablespace_name tbs, b.file_name name, b.bytes / 1024 […]

  • RMAN command details and common summary


    RMAN command details and common summaryCollection and use in the futureLink to this article: https://blog.csdn.net/eviswang/article/details/50448370http://blog.itpub.net/25904686/viewspace-742701/https://blog.csdn.net/zq9017197/article/details/6869579https://www.cnblogs.com/polestar/archive/2013/02/06/2902598.html–HQ? Display RMAN backup information and logshttp://blog.itpub.net/30126024/viewspace-2128114/ [output log][[email protected] script]$ cat rman_db.shexportORACLE_HOME=/u01/oracle/product/ ORACLE_SID=TIGERrman target / cmdfile=/u01/rman/script/rman_db.rcv msglog=/u01/rman/script/rman_full_`date+%Y-%m-%d`.log[[email protected] script]$ 【Catalog】1. Registered copy catalog datafilecopy ‘c:\user01.bak’;2. Register backup catalog backuppiece ‘c:\demo_10.dbf’ ;3. Register all backup files for a specific directory catalog start with […]

  • The solution of reading. Mat file incorrectly in Python


    When importing a local. Mat data file in Python, you will never get the correct data. The problem code is as follows: from numpy import * import scipy.io mnist_train = ‘D:\Machine Learning\TensorFlow\Softmax Regression\mnist_dataset\mnist_train.mat’ mnist_train_labels = ‘D:\Machine Learning\TensorFlow\Softmax Regression\mnist_dataset\mnist_train_labels.mat’ x = scipy.io.loadmat(mnist_train) label = scipy.io.loadmat(mnist_train_labels) print(x.shape) The output of the previous code is (1,1), and the […]