t1 ds1

The test found that even in 11.2, the problem still existed: Sql> SELECT * from V$version; BANNER -------------------------------------------------------------------------------- Oracle database11genterprise Edition release11.2.0.1.0-64bit Production Pl/sql Release 11.2.0.1.0-production CORE 11.2.0.1.0 Production TNS for Linux:version 11.2.0.1.0-production Nlsrtl Version 11.2.0.1.0-production sql> CREATE TABLE T1 2 (ID number, 3 NAME VARCHA

Oracle Database--sql Advanced QueryI. Related content1. Master the multi-table connection query for the SELECT statement.2. Master the subquery of the SELECT statement.Second, the specific operation(a) According to the EMP table and the Dept table under the Scott scheme of the Oracle database, do the following:1. Check the names of all employees who work for clerk and their department name.Select Ename,dname from scott.emp t1 inner joins scott.dept T

Many of the data blocks under the high watermark (HWL) are data-free, but the full table scans to high watermark data blocks, which means that Oracle does a lot of work! Therefore, Oracle provides shrink space defragmentation capabilities. For the index, you can take the rebuild online to defragment, in general, the object that often DML operations DBA to maintain regularly, while paying attention to update statistics in a timely manner!One: Prepare test data , use HR user, create

Label:Database in the daily use of the process, continuous insert,delete,update operation, resulting in the table and index fragmentation is inevitable, fragmentation is more, SQL execution efficiency naturally poor, the reason is very simple, high watermark (HWL) Many data blocks are no data, But the full table scan to scan to the high watermark data block, that is to say Oracle to do a lot of useless! As a result, Oracle provides shrink space defragmentation capabilities. For indexes, you can

Delete bitsCN.com from another table Delete another table based on the table DELETE: how can I DELETE data from multiple associated tables at the same time? Here is an in-depth explanation: 1. delete from t1 where condition 2. delete t1 from t1 where condition 3. delete t1 from

We have talked a lot about how to delete multi-table data in MySQL. The following is an in-depth analysis and discussion on how to delete multi-table data in MySQL, I hope you will learn how to delete multi-table data in MySQL. 1. delete from t1 where Condition 2. delete t1 from t1 where Condition 3. delete t1 from

Oracle automatically clears logs in the materialized view. Oracle determines when to delete the materialized view log based on the registration information on the base table of the Materialized View and the refresh of the materialized view. The registration information of the materialized view is cleared when the materialized view is deleted. However, when the materialized view is created in a remote database, the deletion of registration information may be more complex. If the materialized vie

Student score Table (Stuscore):Name: Name course: Subject Score: Score No.: StuidZhang San Mathematics 89 1Zhang San Languages 80 1Zhang San English 70 1John Doe Mathematics 90 2John Doe Languages 70 2John Doe English 80 21. Calculate the total number of each person and rank (requires display field: Name, overall scores)Answer: Select Name,sum (Score) as Allscore from Stuscore Group by name ORDER by Allscore2. Calculate each person's total and rank (required field: number, name, overall)Answer:

Label:This morning and colleagues hot debate, arguing about the lock on a few basic concepts. Record lock, Gap lock, Next_key lock At that time, I found myself understanding the lock more thoroughly: The isolation level of the transaction is through the lock to achieve AH. RC: Record lock onlyRR: With record and Next_key lock Now let's talk about the lock implementations of various SQL statements in RR mode: CREATE TABLE t1 (ID int primary KEY auto_in

are three columns, each containing several columns. For example, the column-family1 family contains two columns named column1 and column2, T1: ABC, T2: gdxdf is a cell uniquely identified by row key1 and the column-family1-column1. The cell contains two data types: ABC and gdxdf. The timestamps of the two values are different, T1, T2, and hbase returns the value of the latest time to the requester. The spe

))Blob:binary Large ObjectClob:character Large OBJCT#创建数据库Create DATABASE MyDB;#删除数据库Drop database mydb;#查看所有的数据库show databases;#更改当前的数据库Use MyDB;#查看创建数据库的sql语句Show CREATE Database mydb;#创建表CREATE TABLE T1(ID int,Name varchar (20),Age int);#查询表的所有数据SELECT * from T1;#删除表drop table T1;#查看创建表的sql语句Show CREATE table T1;#查看