oracle sql performance analyzer

Label: After a piece of SQL code is written, you can initially predict the performance of the SQL at run time by looking at the SQL execution plan, especially if you find that the SQL statement is inefficient, we can analyze the problem of the

Database engines with excellent design and performance can easily serve thousands of users at the same time. However, the database system of ldquo; underprovisioning rdquo; will greatly reduce its performance as more users access the system at the same time. In the worst case, the system may even crash. Of course, parallel access is the most important issue for any database solution. In order to solve the

each record in the Table. ORACLE optimizes full table scanning by reading multiple data blocks at a time. B. You can use ROWID-based access to access a table through ROWID to improve the efficiency of table access. ROWID contains the physical location information recorded in the table. ORACLE uses indexes to connect data with the physical location where data is stored (ROWID. Generally, indexes provide a q

placed in theundothe table space. This way,Oraclethe reading and writing can be done independently, which is alsoOraclea place of popular praise. SQL Serverread and write are blocking each other, in order to improve concurrency performance, for some queries, you can addNolock, this allows writing to be read, but the disadvantage is that it is possible to read uncommitted dirty data. UseNolockhave a3Rule .

Zone (SGA ). SGA is a full-Process System zone for quick access to database data. If SGA needs to be released and allocated frequently, it cannot achieve quick access to data, therefore, the SGA should be placed in the primary memory instead of in the virtual memory. Memory adjustment mainly refers to adjusting the size of the memory structure consisting of SGA to improve system performance. Because the memory structure requirements of the

dbms_workload_repository. Create_snapshot;We can also use the Dbms_workload_repository package to complete the baseline, modification of the default settings and so on.ADDM (Automatic Database Diagnostic Monitor AWR)is a consultant system within Oracle that can automate some of the optimization recommendations for the most databases, give recommendations for SQL optimization, index creation, and statistics

feedback on the status of each part of the database. 2: The system structure dynamic performance view of the dynamic performance view is a very low-level oracle view, which we seldom need to access. These views are called X $, this view reflects the internal structure of oracle. The X $ view is located at the bottom l

Label:SET STATISTICS profile on: Displays the time, in milliseconds, that is required to parse, compile, and execute the query.SET STATISTICS IO on: Reports information about the number of scans per table referenced in the statement, the number of logical reads (pages accessed in the cache), and the number of physical reads (the number of times the disk was accessed).Set STATISTICS time on: Displays the result set after each query execution, representing the configuration file that the query exe

buffer settings, low buffer hit rateThe cache settings of PGA are too small (for Oracle 9i, when the automatic management mode is used, the PGA settings are too small), resulting in a large number of temporary tablespace operationsRedo logs have performance bottlenecksThe redo buffer settings are unreasonable.Hotspot dataSerious tablespace fragmentationUnreasonable storage parameters for tables and Indexes

Comparison of Oracle Database date filtering methods and oracle Performance When developing SQL statements, filtering date segments is a common problem. How can we efficiently filter out date segments? This article demonstrates through experiments: Method 1: Use to_char to convert a date to a string for comparison To_c

Oracle performance optimization operation 11: try to match the like clause at the front end. oracle clause Because the like parameter is frequently used, if the like clause can be indexed, the query efficiency will be greatly improved. Example: Select * from city where name like '% S % '; The execution plan of the preceding query uses table access full. If it

During the configuration of the maximum performance mode of the physical worker uard, the master database host edbjr2p1 slave Database Host edbjr2p21. create the master database [root @ edbjr2p1 ~] # Xhost + accesscontrol During the configuration process of the maximum performance mode of the physical worker uard, the master database host edbjr2p1 slave Database Host edbjr2p2 1. Create the master database [