Oracle

There are more than 120 queryhint types in Oracle, including undocument, and more than 180, too many. During the development of a large project, the queryhint may be retained so that the final implementer can configure it according to the actual

Yesterday, a server disk was accidentally faulty, and data on drive C was lost. After the operating system was re-installed, the data before the accident was completely restored: After re-installing Oracle according to the original configuration

InProgramWhen defining variables, constants, and parameters, you must specify the PL/SQL data type for them. When compiling PL/SQL programs, you can use the scalar type, composite type, reference type, and lob (largeObject.The most common scalar

1. query the number of connections to the current process of the database: CopyCode The Code is as follows: Select count (*) from V $ process; 2. view the number of connections in the current session of the database:Copy codeThe Code is as follows:

When Oracle EBS operates a form interface or a table in the background database, it is found that the table has been in the "suspended" status. It may be because the table is locked by a user, and other users cannot continue the operation.

If you are familiar with Sequence in ORACLE and want to implement Sequence in SqlServer, you will find that no ready-made Sequence object can be created. What should we do? Of course, this small problem is not difficult for our programmers. "max + 1"

Below is an alphabetical listing of the Oracle system tables that are commonly used. System Table Description ALL_ARGUMENTS Arguments in object accessible to the user ALL_CATALOG All tables, views, synonyms,

As the leader in the relational database market, Oracla plays an important role. Although the operation is not as convenient as SQL Server, its powerful functions attract a large number of followers. As a rookie in ORACLE, I occasionally use Oracle

Since Oracle was used in the project for the first time. Ah, I am ashamed to be troubled by the problem of an auto-increment column for a long time. This is easy to use without SQL Server. Oracle needs to use auto-incrementing SEQUENCE and trigger. 1

Using a cursor, I think this method is absolutely safe.-- First, set a cursor to store the required data in the cursor: Copy codeThe Code is as follows: declare CURSOR D_CURSOR_CUS_INFO IS Select t3.id _ as id _, T3.owe _ money _ as owe_money _, A.

SQL statement for querying and deleting duplicate records1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (peopleId ). Select * from people Where peopleId in (select peopleId from

The relationship between tables is complex, and the data volume is large. Deleting one table by one will definitely cause a big problem. So I tried several solutions, and now I will summarize them. Method 1: Set grading and delete when creating

A cluster is actually a group of tables, which are composed of multiple tables that share the same data block. Combining tables that are frequently used together into clusters can improve processing efficiency; a table in a cluster is called a

The password of scott is incorrect. Go to the Administrator and modify the password of scott. Or change the password as follows: In the running column, press sqlplus (Space)/nolog and press Enter. In the pop-up box, press "conn sys/password as

ORACLE locks have the following modes:0: none1: null2: Row-S Row sharing (RS): Share table lock3: Row-X (RX): used for Row Modification4: Share lock (S): blocks other DML operations5: S/Row-X dedicated shared rows (SRX): block other transaction

Row_number () over (partition by col1 order by col2) indicates grouping by col1 and sorting by col2 within the group, the value calculated by this function indicates the sequential numbers after sorting in each group (the sequential and unique

The syntax structure of the Decode function is as follows: Copy codeThe Code is as follows: decode (expression, search_1, result_1) Decode (expression, search_1, result_1, search_2, result_2) Decode (expression, search_1, result_1, search_2, result_

UPDATE 1. Back up data first (security and performance improvement ). 2. Batch update and batch commit to prevent lock tables. 3. If the updated index automatically has a large volume of data, the index will be canceled first and then

Directory structure: 1 _ crazy Java _ crazy software _ Xiao wenji instructor _ Oracle_Oracle Server InstallationThe video includes: Download, installation, uninstallation, and precautions for Oracle10g servers.2 _ crazy Java _ crazy software _

In principle, the Recycle Bin is a data dictionary table that stores information about database objects deleted by users. Objects deleted by a user are not deleted by the database and still occupy space. Unless the user Purge manually or the