Recommended 10 commonly used retention usage, welcome to download!

retention annotations Retention (reserved) Note that this type of annotation is retained at that stage. There are three values: 1.retentionpolicy.source--This type of annotations is only preserved at the source level and is ignored at compile time by 2. retentionpolicy.class--This type of annotations is preserved at compile time and exists in the CLASS file, but the JVM will ignore 3.retentionpolicy.runtime-- This type of annotations will be retained by the JVM, so they can be read and used by the JVM or other code that uses the reflection mechanism at runtime. Example 5 demonstrates the Retentionpolicy.runtime declaration: Example 1 of Java annotations: @Retention (retentionpolicy.runtime) Public @interface test_retention

1. Java annotations retention, documented, inherited introduction

Introduction: This article mainly introduces the Java annotations retention, documented, inherited annotation introduction, this article and related articles is a series of articles, the need for friends can refer to the following

2. Spring AOP extracting Redis instances

Introduction: 1. Define annotations Package com.efoxconn.ipebg.common.annotation; Import Java.lang.annotation.ElementType; Import java.lang.annotation.Retention; Import Java.lang.annotation.RetentionPolicy; Import Java.la ...

3. Immediate_sync Properties of transactional replication

Summary: The Immediate_sync property of the transactional replication is closed by default, which can be specified when the publication is created, or it can be modified after creation. If Immediate_sync is true, the snapshot file and replicated transaction are persisted to data retention.

4. Oracle Flash back table based on SCN number

Summary: We recommend changing the Undo_retention parameter when installing Oracle software, we recommend changing the value of default 900 to 10,800 seconds, or 3 hours; alter system set Undo_retention=1

5. Oracle Backup Retention policies (RETENTION policy)

Summary: The backup Manager Rman provides the Configure RETENTION policy command to set the backup save strategy, which is how long the backup file is set to remain. Rman will have the time-out backup text

6. The difference between obsolete and expired in Rman backup

Summary: Obsolete: Associated with retention policy, the state is flagged when the backup or copy is discarded according to the save policy. For example, you set the recovery window to 7 days,

7. Oracle Read Consistency Learning note

Summary: In order to avoid ORA-1555 snapshots being too old, the Undo_retention parameter indicates how long the data in the undo block used by the transaction needs to be retained after it is committed or rolled back.

8. Oracle Undo Table Space Size estimate

Brief: (UR) undo_retention in seconds (UPS) Number of the UNDO data blocks generated per second (DBS) Overhead varies based on ext E

9. How to estimate the size of the undo table space required by the Oracle database

Summary: To determine the size of the undo tablespace required by Oracle, the following three pieces of information are required: UR in seconds, undo_retentionups per second, of the restored chunks generated

Oracle Undo Table Space Routine maintenance view operations

Summary: Undo table Space Common operations: (1) View undo Tablespace undotbs1 Properties: sqlgt; Select B.tablespace_name,autoextensible,retention F

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