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Question: I’ve just been handed a new Linux Server build, on a new storage system. The RAID levels are different and the storage parameters have changed. I need to measure the IO performance of the new system and compare to the current system.
DB2 will be deployed on these servers, which are ver......
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Executing a t-sql statement with a convert function
convert(datetime, my_date_column) ,
threw an arithmetical overflow error with the message :
Message
Arithmetic overflow error converting expression to data type datetime. [SQLSTATE 22003] (Error 8115) The statement has......
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To generate the ALTER INDEX..DISABLE and the ALTER INDEX..REBUILD statements for all nonclustered indexes for a single table use the following sql statements.
Copy and Paste the statements, execute on the database. I’ve included the URL column for easy click through to some notes on the code
1......
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IBM DB2 documentation is very comprehensive. But I still like create and maintain my own documentation\scripts for repeatable tasks. Installing DB2 should be an efficient process, customised to a particular environment.
I maintain all DB2 documentation on the network and my laptop. One of the ma......
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Use the script below to rebuild an index on a table
ALTER INDEX MY_INDEX_NAME on MY_TABLE_NAME REBUILD;
Check SQL Server BOL for a the full list of options
Notes
1) Issuing an Index Rebuild request, drops and recreates the index
2) If rebuilding a CLUSTERED INDEX, nonclustered index......
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Part of the Performance Tuning series – Performance Stack, this section looks at Access Path Tuning. How does the user access the data and how can the access be maintained. The purpose of the series is a general approach to Performance Tuning – independent of database server platform. A large ......
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Use the script below to disable an index on a SQL Server table
ALTER INDEX MY_INDEX_NAME on MY_TABLE_NAME DISABLE;
Executing the code will prevent access to the index.
If it’s a CLUSTERED INDEX, the data remains intact on the table, but no DML can access the data. Drop the index or rebuild......
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Tuning DB2 is critical if Websphere Portal is the main client. In larger Websphere Portal architectures, where load balancing is standard, this become obvious.
Follow these general guidelines to achieve faster response times on Portal requests. These guidelines don’t replace baselining\monitorin......
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Fragmentation of an index can severely affect performance. When logical ordering of the key within a page does not match the physical ordering within the data file, fragmentation exists.
I execute index maintenance scripts for databases on a regular basis. If I’m executing a custom job, such as ......
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When a DB2 database starts the total memory required for the bufferpools must be available.
If this memory is not available when a database starts, the database manager will only start with system buffer pools (one for each page size) with a minimal size of 16 pages, and an SQL1478W (SQLSTATE0162......
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