commit sql

Speaking of HWM, we first need to talk briefly about Oracle's logical storage management. We know that Oracle is divided into 4 granularity on logical storage: tablespace, segment, region, and block. (1) Block: Is the smallest granularity of storage

Reference one, explicit cursorExplicit is relative to the implicit cursor, there is a clear statement of the cursor. The declaration of an explicit cursor resembles the following (verbose syntax participates in Plsql ref doc):Cursor cursor_name

Today's simple summary of the use of cursor (cursor/cursor) in Pl/sql.I believe that many DBAs who do development or maintenance have encountered similar problems when looking for a job: simply describe the type of cursor, the difference between a

Wm_concat is useful when you are in rows, but scheduling problems are often difficult to control during row-and-column transfers. The following examples are visible:Prepare test table:drop table t;CREATE TABLE t (n number,m number);INSERT into T

1, must set the undo retention time is large enough to be able to reconstruct the required flash back data The ALTER SYSTEM SET undo_retention= seconds value is the number of seconds that the UNDO data is persisted. Flashback view is

1. Overview of the OracleTransaction Class (from MSDN)The application creates OracleTransaction objects by calling BeginTransaction against the OracleConnection object. Performs all subsequent operations associated with the transaction (for example,

1, SavePoint (set up the savepoint, used to roll back to the savepoint when the error)Establish the savepoint A1:savepoint A1;............................ [A lot of things were done in the meantime]Then establish the preservation point A2:savepoint

Reprinted from: http://blog.csdn.net/leshami/article/details/5731158One, rollback (ROLLBACK) and undo (undo)Rollback and roll forward are important means of ensuring that the data in an Oracle database is in a consistent state. --Before the 9i

Grouping Functions , multi-line functions Summary of non-null dataOnly Lieri the null value first.Grouping is not requiredSql> Select COUNT (*), sum (Salary), AVG (Salary), min (Salary), Max (salary) from employees;sql> CREATE TABLE t1 (x int);sql>

1, the acid characteristics of the transaction: atomicity atomicity, consistency consistency, isolation isolation, durability persistence.2, the operation of the transaction① Transaction Commit sql>commit;   ② Transaction Rollback sql>rollback;     ③

1. Why use stored ProceduresThe process of using T-SQL statements to the server by an application is unsafe.1) Data not secure2) Each commit SQL code will be executed after syntax compilation, affecting the performance of the application running3)

http://blog.csdn.net/gyflyx/article/details/6889028Reference one, explicit cursorExplicit is relative to the implicit cursor, which is the cursor with a clear declaration. The declaration of an explicit cursor is similar to the following (the

Database type: Hierarchical databases (hierarchical database, HDB) The data is represented in a hierarchical structure (tree structure). relational databases (relational database, RDB) Use specialized SQL (structured

"LJ?" Dragon "The fish said to the water that you could not see my tears, for I was in the water." Water says I can feel your tears, because you are in my heart. "LJ?" Dragon "You" re more than a shadow, I ' ve just to believe. "LJ?" Dragon "A true

When using DataStage development, you encounter an error:Sql*loader-951:error Calling Once/load initializationOra-00604:error occured at recursive SQL level 1Ora-00054:resource busy and acquire with NOWAIT specifiedMove out of Google's big God:It is

The new features of In-database archiving are introduced in Oracle Database 12c, which allows users to archive data by marking data rows on the table as inactive inactive. These inactive data rows can be compressed into one optimization and are not

Data Manipulation languageDML can be performed under the following conditions:– Inserting data into the table– Modify existing Data– Delete existing dataA transaction is made up of DML statements that do several thingsAdd a new data –insert

Organize a few sections of common C # code that operates on SQL Server Mobile databases for reference by a friend who has just contacted SQL Server Mobile development.1. Create a databaseCreate a databaseFile.delete ("Test.sdf");SqlCeEngine engine =

The following is the DataAccess Universal database access Class I wrote, simple and easy to use, support: inline create multiple parameters, support multi-transactional submissions, support parameter reuse, support replacement database type, hope to

Cascade Delete, such as when you delete a table and then add the keyword, will delete the table and delete the relationship between the tableotherObject1. Cascade delete the information in table A, when the field in table A refers to the field in