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[20140213]再论行迁移.txt
[20140213]再论行迁移.txt 昨天看jonathanlewis的blog，链接如下： https://jonathanlewis.wordpress.com/2014/02/10/row-migration/ Oracle behaves quite intelligently with migrated rows. First, the migrated row has a pointer back to the original location and if the row has to migrate a second time th...
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How to Estimate Table Size
By Alexander GeldutesSuppose, you have to create a new table and insert some data into it, or table already exists and you will make inserts. You want to estimate the final size of your table, for example you want to set correct storage parameters.You can do it in two ways: Using internal statistics. Math estimation. It's very rough estimation. [@more@]I-st method - using statistics Analyze statitics for the table.From SQLPlus run the following command:ANALYZE TABLE <table_name> COMPUTE ST
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Oracle临时表
一、什么是临时表Oracle的临时表只在事务(transaction)或者会话(session)期间保持数据。临时表中的数据对于会话(session)来说是私有的，这意味这每个会话只能查看和修改自己的数据。对于应用程序而言，临时表对于一些需要暂时缓存的数据是非常有用的。二、创建临时表CREATE GLOBAL TEMPORARY TABLE语句创建一个临时表...
