Oracle

Query table Space usage 　　 Select A.tablespace_name "Table space name", 100-round ((NVL (b.bytes_free,0)/a.bytes_alloc) *100,2) "occupancy rate (%)", Round (a.bytes_alloc/1024/1024,2) "Capacity (M)", Round (NVL (b.bytes_free,0)/1024/1024,2

After groping and practicing, I put my own solution, written in the following: Description The version of my Oracle client is Oracle 9i, when the client side is installed, you cannot use the default installation, be sure to customize it, and then

Recently because to write a project interface, the need to remotely connect the Oracle database, just at the beginning because I installed a local MySQL, so used to connect the local MySQL, the interface is generally finished in Tomcat test under,

For example, now there is a person table (table name: peosons)If you want to have the name, ID number, address of these three fields exactly the same records query Copy Code code as follows: Select p1.* From persons p1,persons P2

The Oracle tutorial being looked at is: Oracle Database Security Policy Analysis (ii). Security for the SQL*DBA command: If you do not have a sql*plus application, you can also use SQL*DBA to do SQL check permissions, which can only be assigned to

The Oracle tutorial you are looking at is: Oracle 8i installation on P4. Method One: 1, copy the Oracle software to the hard disk. 2, the hard disk directory file STAGECOMPONENTSORACLE.SWD.JRE1.1.7.30/1 DataFilesExpandedjrewin32binsymcjit.dll's

The examples in this article describe the use of Oracle triggers. Share to everyone for your reference, specific as follows: Introduction of Triggers The definition of a trigger is that when a condition is set up, the statement defined within the

A foreign key specifies that the value of a column (or a group of columns) must conform to the values of some rows in another table. We say this is to maintain the referential integrity of the associated table.In the graphical interface, the Foreign

Oracle's SUBSTR function simple usage SUBSTR (string, intercept start position, intercept length)//return the intercepted word substr (' Hello World ', 0, 1)//return result is ' H ' * to intercept a string with a length of 1 starting from the

This article to share the Oracle trunc function processing date format related knowledge, very has the reference value, concrete please see below explanation. Copy Code code as follows: Select To_char (sysdate, ' Yyyy-mm-dd

The Oracle tutorial being looked at is: Oracle SQL Performance Tuning series learning one. 1. Choose the appropriate Oracle OptimizerThere are 3 Oracle optimizer types:A. Rule (rule-based) b. Cost (based on costs) c. CHOOSE (optional)Set the default

The Oracle tutorial is looking at the power of multiple CPUs with Oracle parallel queries. Parameters Let's take a closer look at how the number of CPUs affects these parameters. Parameter Fast_start_parallel_rollback One exciting thing about

The Oracle tutorial you are looking at is: Oracle 9i easy access to table and index DDL statements. We all know that before 9i, it would be a hassle to get the statements to build tables and indexes. Our usual practice is to come through the export

The Oracle tutorial you are looking at is: a brief discussion of Oracle database set replication methods. Objective The growing demand for distributed applications requires a better distributed software environment, which drives the development of

Oracle provides index monitoring features to determine whether an index is in use. In Oracle 10g, collecting statistics will allow indexes to be monitored, and this phenomenon no longer exists in Oracle 11g. However, this method only provides that

ASP (Active Server Pages) is one of Microsoft's tools for developing Internet applications, and the ASP's connection to the database is typically done through ADO (Activex Data Object), like the computer World March 20, 2000 As described in the ASP

Since 9i, Oracle Dataguard generally do not need to manually process the lost log, FAL will automatically help us deal with, the following case by hand to handle the Lost log method: 1. What logs are missing from the standby query and not applied

Looking at Oracle data recently, understand the concept of rownum, previously only know the database table for simple additions and deletions to check; After seeing the concept of rownum, it suddenly occurred to me that many business scenarios

Oracle Modify Field Name ALTER TABLE XGJ Rename column old_name to new_name;Modify a field type ALTER TABLE tablename Modify (column datatype [default value][null/not null],....);Example Assuming table xgj, there is a field name, data type char (2

Import MySQLdbImport cx_oracle as OraImport Pandas as PDFrom SQLAlchemy import Create_engineFrom Settings Import DATABASESFrom sqlalchemy.sql.sqltypes Import *From math import isNaNConnect to MySQLConn_mysql = MySQLdb.connect