oracle query optimization tool

conditions. 2. Because php requires lost for all variables after execution, you can consider: Solution a. Create a temporary table in mysql and insert the query results with a time or random number as the unique marker. Create page1 ~ Pagen fields, each field stores the ids required on the page, such an id for a record. solution B. if you open the session, you can also save it in the session, which is actually saved in the file. Create a $ IDs array,

Tags: store style col MySQL share picture lob Div using indexfirst, MySQL's slow query log opening and storage 1, check whether the SQL records that do not use the index to the slow query log, view the log_queries_not_using_indexes variable; like "Log_queries_%" Results: If the value of the query is off, it indicates that there is no record, set to on to open

, find the corresponding IDs, with the "," interval: select * from $ table where id in ($ ids); the speed is definitely 4. when closing the query, You need to automatically clear the query results. You can set the timing or random ratio. If you want to add a time Sign field to the temporary mysql table, $ IDs ["time"] = time () must be added to the session. If you do not perform this operation after a certa

oracle| Performance | execution The cost of using the Oracle execution planning mechanism to improve query performance the time of the new SQL statement is the most important part of the Oracle SQL statement execution time. But by understanding the mechanism within Oracle to

1. ADDM provides an overall optimization solution. Based on AWR snapshots for a period of time, you can perform ADDM analysis to diagnose possible database bottlenecks during this period. It does not need to be installed, and the analysis results are automatically provided. statspack needs to be installed, and the generated analysis report needs to be analyzed by DBA.1. the ADDM tool requires that the syste

xh_bz = 1 condition is only 0.5%,When the first SQL statement is executed, 99% records are compared with dy_dj and xh_bz. When the second SQL statement is executed, 0.5% records are compared with dy_dj and xh_bz,The CPU usage of the second SQL statement is obviously lower than that of the first SQL statement.B. query the influence of table orderThe list order in the table after FROM will affect SQL Execution performance.

db_block_lru_latches parameter. Example: modify or add the following two parameters db_writer_processes=4db_block_lru_latches=8 A and 2 enable asynchronous I/O. IBM is much simpler in this aspect, while HP is a little more troublesome. You can contact HP engineers. B. DB file sequential read refers to sequential read, that is, full table scan. This is also the part we should minimize. The solution is to use indexes and SQL

. Maybe it attracted me to use the SQL syntax, at least it is easy to use the system information obtained by "windows optimization master. I have been working on this small program at night. Because WMI is designed to cover all aspects of windows, I want to develop a query analyzer tool for SQL Server to debug WMI queries; it is easy to use ,. net provides a Syst

rapidly as the number of records increases. SQL statement instead: Select*from s,sc WHERE score>70 and S.sno=sc.snoThis join query statement overcomes the above shortcomings, first to filter out the matching records, reduce the number of records to join, and then execute the join query, greatly improving the query efficiency. 3 concluding remarks

Label:(1) Select the most efficient table name order (valid only in rule-based seo/' target= ' _blank ' > Optimizer):The ORACLE parser processes the table names in the FROM clause in a right-to-left order, and the FROM clause is written in the final table (the underlying table, driving tables) will be processed first, and in the case where the FROM clause contains more than one table, you must select the table with the fewest number of record bars as

Io OptimizationIn the case of massive data, more than 80% of database performance problems are related to Io, So I/O optimization is an important task throughout the whole process of massive database management.I/O optimization involves a wide range of aspects, and I/O optimization focuses on some major aspects of Oracle