top 10 database software

Problem How to randomly extract 10 items from a database? Workaround There is no good solution, the efficiency is high, the method is simple. Reference answer If you have a cache system .... Load directly from the cache .... Reference answer No ~ Reference answer Random syntax ... Reference answer Why not use the RAND function Reference answer Rand is definitely going to use it, but I don't know how to wr

The OS package and OS patch required for installing oracle database 10gR2 under Solaris 10 or later, sparc10gr2 Reference: Oracle Database (RDBMS) on Unix AIX, HP-UX, Linux, Mac OS X, Solaris, Tru64 Unix Operating Systems Installation and Configuration Requirements Quick Reference (8.0.5 to 11.2) (Document ID 169706.1) Required Packages: SUNWarc, SUNWbtool, SUNWh

In Oracle Database 10 Gb, this restriction disappears: as long as the operating system has the same byte order, you can transmit tablespaces between platforms. This article will not expand the length of the byte sequence In the Oracle Database 10 Gb, this restriction disappears: as long as the operating system has the

number of rows. After you perform a select ... for update, other select...for update queries for this data are blocked, but the normal select table is not affected.optimistic lock controlControlled with a timestamp or version number. The user does not lock when reading the data, but the control field is also detected together when querying the data. When the user updates, check that the value of the control field in the database is the same as the va

Oracle 11g Silent Installation Software + manual database creation Because it is a secondary jump + remote operation, the GUI cannot be used and cannot be directly installed on the GUI. Use silent software installation + manual database creation to complete the requirement. 1. Install the Oracle

After the CentOS system is installed, you can start the installation of Oracle 11g. First, you must make some preparations. Use commands to create an Oracle account and corresponding user groups Create a folder and grant the Oracle user permissions, as shown in the commandUse the root account to make a series of changes to the corresponding system files, and use the oracle account to set directories such as ORACLE_SID, ORACLE_BASE, and ORACLE_HOME. (The specific settings are similar to those f

/temp01.dbf'Size 20 mUndo tablespace undotbsDatafile '/opt/Oracle/oradata/undotbs01.dbf'Size 200 m autoextend on maxsize unlimited;7. create other system tablespacesCreate tablespace users loggingDatafile '/opt/Oracle/oradata/users01.dbf'Size 25 m reuse autoextend on next 1280 K maxsize UnlimitedExtent management local;Create tablespace indx LoggingDatafile '/opt/Oracle/oradata/indx01.dbf'Size 25 m reuse autoextend on next 1280 K maxsize UnlimitedExtent management local;8. Run the data dictionar

1. Install the operating system Oracle Enterprise Linux 5.2 2. Create a user Create an oracle user, create a dba group and an oinstall Group[Root @ oel_11g ~] # Groupadd oinstall[Root @ oel_11g ~] # Groupadd dbaThen, create a directory/u01/app/oracle under the root directory. We plan to install the Oracle11G software in the/u01/app/oracle directory.Create user and passwordAdd an oracle user with the password: oracle. The primary group is oinstall. The

Tags: Enter upgrade deployment version cell structure log file many build Database Upgrade maintenance strategy in software development stage Why maintain an upgrade 1.1 Status and emerging issues If you develop a project that does not use the database, then you do not have to maintain the database. If you develop a

Source: CCID1. Install the latest service packageTo improve Server security, the most effective method is to upgrade to SQL Server 2000 Service Pack 3a (SP3a ). In addition, you should install all released security updates.2. Use Microsoft Baseline Security Analyzer (MBSA) to evaluate server securityMBSA is a tool that scans insecure configurations of multiple Microsoft products, including SQL Server and Microsoft SQL Server 2000 Desktop Engine (MSDE 2000 ). It can run locally or through the net

index on a field of char (40)) can cause a large amount of I/O overhead (even more than the I/O overhead of the table scan). Therefore, try to use an integer index. (6) If the value of a field may be empty, do not index the field. (7) The number of large table indexes is no more than 5, and the maximum number of fields in the composite index is no more than 5. (8) In database scripts, avoid using the or condition as much as possible, because the o

Starting from 10 Gb, oracle began to provide Shrink commands. If our tablespace supports automatic segment space management (ASSM), we can use this feature to narrow down the segment, that is, reduce the HWM. Here we need to emphasize that this new 10g feature is only valid for the ASSM tablespace, otherwise the ORA-10635: Invalid segment or tablespace type will be reported. Here, we will discuss how to recycle wasted space for an ASSM segment. Simila

= np.concatenate (ys) del X, Y13 Xte, yte = Load_cifar_ Batch (Os.path.join (ROOT, ' Test_batch ')) return Xtr, Ytr, Xte, Yte——————————————————————————————————————————————There are several statements to note:X = X.reshape (10000, 3, +, 1). Transpose (0, 2, 3,). Astype ("float")At first, the size of X is (10000, 3072 (3*32*32)). First of all, reshape is well understood, and the final Astype format conversion is also well understood.But why call transpose and transpose axes? I think it's ju

and can be modified by modifying the MY.CNF option Ft_min_word_len=3 But! Full-text indexes are not exactly equivalent to fuzzy queries For example, the title field has such data ' ABCD20088CCAA ', using a fuzzy query select * from articles wheretitle like '%2008% ' can be found, while using full-text Search select * from articles where match (title) against (' 2008 ') is not retrieved because 2008 is not a word! 4) using the full-text Search engine Toolkit A segment string can be retrieved us

addition to the above four kinds of SQL language, but also related to the concepts of tables, indexes, stored procedures and transactions, they are also indispensable in practical programming.In the actual software development project. Dealing with a variety of databases is a common occurrence. In the daily work of the author. There are two types of databases that are used frequently: theSybase database an

I checked the various versions of DB2. It is said that DB2 10 has come out and I don't know what the situation is, but it will definitely improve some functions, this article is my summary of the latest DB2 9.7 database version planning: DB2 Express-C Limited to support up to 2 CPU cores and 4 GB memory, of course, this version of the DB2 installation package can be used for development and testing for free

addition to the above four kinds of SQL language, but also related to the concepts of tables, indexes, stored procedures and transactions, they are also indispensable in practical programming.In actual software development projects, dealing with a variety of databases is a commonplace. In the daily work of the author. There are two types of databases that are used frequently: theSybase database and the Ora

An error occurred while importing the dmp exported from Oracle 11G to the 10g Database.(IMP-00010: Failed header verification because it is not a valid exported file) SolutionBecause the server has oracle 11 GB and oracle 10 Gb locally, the dmp files exported from the server are displayed as: IMP-00010: it is not a valid file to be exported. After the header verification fails, I found the following informa

Tags: mysql mariadb linux centos7#!/bin/sh # user_db= "root" pass_db= "passwd" host_db= "localhost" name_db= "Mysqlname " Port= "3306" ls/bak/mydata/>/dev/null if [$?-ne 2];then mkdir-p/bak/mydata >/dev/nullAutomatically backs up MySQL database and automatically deletes backups from 10 days agoAutomatically backs up MySQL database and automatically deletes backup

SQLBackupAndFTP is mainly used to automatically back up the database, restore the database with one click, send the backup database log report to the mailbox, automatically compress the backed up database, and regularly execute Database Backup tasks to replace the SSMS maint