db2 performance tuning tips

, which can significantly improve performance. Experience shows that the biggest improvement in SQL Server performance is due to logical database design, index design, and query design. Conversely, the biggest performance problems are often caused by deficiencies in these same areas. In fact, the essence of SQL optimization is that the result is correct, with th

prevents people from overwriting the length () method. In addition, if you specify a class to be final, all methods of that class are final. the Java compiler will look for opportunities for inline (inline) all final methods ( This is related to the specific compiler implementation ). This will increase the performance on average 50%. 1.6 Use local variables as much as possibleparameters that are passed when the method is called and temporary varia

/how-to-drastically-improve-your-app-with-an-afternoon-and-instruments) There are some code that can be used to parse the ISO-8601 date string, and simply rewrite it to use it.Well, just use C to make it look good, but do you believe that we have a better plan!If you can control the date format you are working with, try to choose a Unix timestamp. You can easily convert from timestamp to NSDate: -(nsdate*return[NSDate datewithtimeintervalsince1970:timestamp];}This will be faster than using C

) name:@"IdleNotification" object:nil]; NSNotification *notification = [NSNotification notificationWithName:@"IdleNotification" object:nil]; [[NSNotificationQueue defaultQueue] enqueueNotification:notification 　　postingStyle:NSPostWhenIdle];} Five, memory optimization Use Autorelease pool to reduce memory spikes Six, Code details optimization 1, not in the viewwillapear time-consuming operation 2. If the key code is more efficient with C/C + + Seven, picture optim

some code that can be used to parse the ISO-8601 date string, and simply rewrite it to use it.Well, just use C to make it look good, but do you believe that we have a better plan!If you can control the date format you are working with, try to choose a Unix timestamp. You can easily convert from timestamp to NSDate:-(nsdate*) Datefromunixtimestamp: (nstimeinterval) timestamp {return [nsdate Datewithtimeintervalsince1970:timestamp]; }This will be faster than using C to parse the date string!It is

add the following line to the boot auto mount in the/etc/fstab file: /dev/sdb1/ssd ext3 defaults00 Now we move MySQL to the new diskFirst stop the MySQL service: #service mysqld stop I suggest you?? Stop Apache/nginx at the same time to prevent any attempts to write to the database: #service httpd stop #service nginx stop Now copy the entire MySQL directory into the new partition: #cp/var/lib/mysql/ssd/-Rp This may take some time, depe

Tags: Practice login 16px between multiple connect shut down database SQL business logic　　The end of 2016 was the stage where I learned to understand the entire front end, backend, and database programming. During the practice programming process, notice that there is a scene between the server and the database: Start linking Database SQL--- $loginin =mysql_connect ("192.168.10.253:3306", "root", "123456"); To the end of the entire business logic, do not add a channel that closes the SQL linked

Windows 2000 TCP Performance Tuning tips Carl HarrisCommunications Network servicesvirginia tech I was dismayed by the rather dismal TCP Performance in Win2000, especially for FTP up/downloads to distant sites, where the round-trip time (RTT) is nearly triple-digit. being a Unix bigot of sorts, I also found it amusing

the data processing to the SSAS Cube Dimension (also disk files), again generate unequal disk overhead, in addition to distinct to recalculate, the former need to the membership dimension of this large table to do tier to heavy, the latter only need to the membership level this small dictionary table to do the heavy, obviously the calculation is different weight class, These are just the cost of the process, perhaps you are doing in the night, not care these, then the

The DB2 tutorial you're looking at is: Tips for improving Insert performance in DB2 (1). Overview of the INSERT processing processFirst let's take a quick look at the process steps when inserting a row. Each of these steps has the potential to optimize, which we will discuss later. Prepare the statement on the c

Tags: process optimizer consolidation requires merging auto overwrite session accessThe full execution order of the SELECT statement:The full execution order of the SQL SELECT statement: 1. The FROM clause assembles data from different data sources; 2. The WHERE clause filters the record rows based on the specified criteria, 3, the GROUP BY clause divides the data into multiple groupings, 4, uses the aggregation function for the calculation, 5, uses the HAVING clause to filter the grouping; 6, e

an execution plan, and stored in a database of SQL statements, is a collection of control flow language, the speed of course fast. 48, the return value of the function is not too large, this overhead is very large. A user-defined function that executes as a cursor consumes a large amount of resources if a large result is returned with a stored procedure. 49, as far as possible to avoid repeated access to the same or several tables, especially the large number of data tables, you can consider th

Server and DB2 also rely on statistics, and even open source relational libraries rely on statistics, but the mechanisms and details they generate and implement are somewhat different. For example, Oracle provides a large number of Hint,sql server and DB2 also provide hint this tuning method, but the role of specific hint and syntax, some versions of the Open So

using Delphi, C++builder, or Kylix, some tips and guidelines will help you make sure you get good performance when accessing DB2 data. For example, in some cases, using Dbexpress TM instead of ODBC/JDBC or ADO can improve query performance. Dbexpress is a cross-platform interface for processing dynamic SQL from Delphi