tuning oracle sql queries

Label:Original: SQL Server Tuning Series BasicsObjectiveAbout SQL Server Tuning series is a huge content system, not a word two words can be analyzed clearly, this article first in the SQL tuning in the most commonly used query pl

Oracle 11g has made some improvements in optimization. Oracle automates the following optimization: Redo Logfile Sizing Advisor-this feature recommends Redo the optimal size of log files to avoid excessive disk I/O caused by frequent checkpoints. Automatic Checkpoint Tuning-Oracle database can now optimize checkp

at the statement level, the hint syntax is:/*+ bind_aware*/;Ø about outlines: In the scene of outlines existence, the ACS will fail whether the system level is enabled or the statement level is enabled through hint;6. Conclusion:New features of Oracle Database 11g The ACS feature provides an easy way to efficiently share SQL statement execution plans with bound variables. Because ACS produces a new executi

ObjectiveAbout SQL Server Tuning series is a huge content system, not a word two words can be analyzed clearly, this article first in the SQL tuning in the most commonly used query plan to parse, to do a good job of the basic grasp, tamping basic skills! Then we talk about the overall statement tuning.Learn how to read

ObjectiveAbout SQL Server Tuning series is a huge content system, not a word two words can be analyzed clearly, this article first in the SQL tuning in the most commonly used query plan to parse, to do a good job of the basic grasp, tamping basic skills! Then we talk about the overall statement tuning.Learn how to read

Have always wanted to summarize the knowledge of Oracle memory tuning, recently optimized a database memory parameters, look for some information and Google a lot. Now write it down and do the backup. First, overview: Oracle memory can be divided into the system global zone and the process global area in terms of shared and private, that is, the SGA and the PGA

increase simultaneous throughput Determining income Determining costs monitoring tasks for common bottlenecks Monitor memory consumption Monitor thread and CPU usage Monitor HDD IO Monitor low performance queries Monitoring stored procedures, SQL, and user activity Monitor current locks and user interactions Build a performance

gp4.1 and previous SQL with not in will be executed with Cartesian product, using nested join, very poor efficiency Not in== use the left join to go back to the table Association to implement Example select * from test1 where col1 not in (select col2 from test1)Switch select * from test1 a left join (select col2 from test1 group bycol2) b on a.col1=b.col2 where b.col2 is nullThe run time is increased from more than 30 seconds

This series of "T-SQL" is mainly for T-SQL summary.T-SQL Basics"T-SQL Basics" 01. Single-Table query-several SQL query questions"T-SQL Basics" 02. Join Query"T-SQL Basics" 03. Subquerie

ObjectiveIn the previous articles, we introduced a series of descriptions of operators and the optimization methods and techniques for each operator. This includes a series of our common operators, including how to view execution plans, how several datasets are commonly used, how to join operators, and parallel operators. Interested children's shoes can be clicked to view.In this article we introduce a series of sub-query statements, sub-query is generally the formation of some of the basic oper

problem in more detail by querying the store. In SSMs Object Explorer, SQL Server 2016 provides a new node called the query store, where you'll see some reports. The first few resource usage queries show you the most expensive queries, based on the dimensions you choose. Switch to "logical read Count" here. Here are some q