oracle pl sql performance tuning

-------------------------------------------------------------------------| Id | Operation | Name | Cost (%CPU) |-------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 4 (0) || 1 | TABLE ACCESS by GLOBAL INDEX rowid| SALES | 4 (0) || 2 | INDEX RANGE SCAN | Index_qu_sold | 3 (0) |-------------------------------------------------------------------------9 Rows selectedSql> alter session Set "_use_nosegment_indexes" =true;Session altered.Sql> CREATE index

Three Join strategies in the execution planThere are three join strategies for SQL Server: Hash join,merge join,nested Loop join.hash Join: Used to handle data that is not ordered/not indexed, it creates a hash table in memory of the data (the associated key) on both sides of the Join. For example, with the following query statement, the associated two tables are not indexed, and the execution plan is displayed as a hash Join.SELECT sh.*from salesor

The DBMS_HPROF package is an oracle11g tool. It is a combination of DBMS_PROFILER and DBMS_TRACE. Here is a simple demonstration of how to use the DBMS_HPROF package to analyze the stored procedure information. The DBMS_HPROF package is a tool that appears in oracle 11 GB. It is a combination of DBMS_PROFILER and DBMS_TRACE. Here is a simple demonstration of how to use the DBMS_HPROF package to analyze the stored procedure information. The DBMS_H

/SQL program design, including basic grammar, control structure, cursor, exception handling, etc. the most practical development techniques for PL/SQL programs are introduced, including subroutines, packages, triggers, dynamic SQL, batch bindings, subroutine dependencies, etc. advanced article describes

. Create_snapshot; We can also use the Dbms_workload_repository package to complete the baseline, the default settings and other operations.ADDM (Automatic Database diagnostic Monitor AWR)Oracle is an internal consulting system, can automatically complete the most database of some optimization recommendations, giveSQLThe optimization, the creation of the index, the collection of statistics and other suggestions.ADDM report Generation:Sqlplus>@?/rdbms/

feature that accelerates SQL adjustment as a whole.Through SPA, once a load (called SQL tuning set or STS) is created, Oracle will use the complex prediction module to repeatedly execute the workload (To obtain the best SQL Execution Plan for the current load. With SPA, we

T-SQL is an enhanced SQL language provided by SQLServer based on the SQL language. The T-SQL provides all the features of ANSISQL and adds more features such as extended functions, system pre-storage, and program design structures. The following describes 3. the T-SQL of

of disk sorting will be greatly increased. This is mainly because at the end of the month, users will make statistics on the transaction data for the month. So at the beginning of the month, because of the number of transactions, so there will be more disk sorting occurs. In this case, it is necessary for the database administrator to adjust the relevant parameters. However, this adjustment is a temporary adjustment, until the cycle has passed, still need to transfer the parameters back. Only i

Method 1: As we all know, to connect to Oracle using PL/SQL, you need to install the Oracle client software. Have you ever wondered whether to directly connect to Oracle without installing the Oracle client? In fact, I always

the deterioration of performance is a variety of factors, and sometimes the results of the performance degradation caused by multiple elements, this requires the database administrator has a more comprehensive computer knowledge, can be sensitive to the impact of the database performance of the main reason. In addition, good database management tools are also im

Oracle Database 10g Performance Tuning tips and techniques is recommended. For Oracle performance test, diagnosis, analysis, and optimization, see! Chapter 2 Basic index principles (beginner developer and beginner dBA). For Oracle