The Metering System Database Migration And, In A Heterogeneous Environment

Based on data migration of the weighing measurement system in the pratical production application, this thesis focus on how to help users of the ORACLE database solving the data migration.The weighing measurement system is one of the core business in Shanxi branch of CHALCO, its database and business applications is installed on the same PC server. Because the bugs of WINDOWS operating system and the server's performance drawbacks, we need to migrate the database smoothly to the ORACLE database based on the IBM minicomputer platform. So it rings the problem that what kind of methods can we take to complete the database migration. And it is the topic that my thesis talks about.The First, the thesis introduced the three-layers Schema of the database structure including Schema, External-Schema and Internal-Schema which covering the logic and physical level of the database. Right because of this three-layers Schema concept and the data physical and logical independence,the database application to achieve business-system programming and the follow-up maintenance operation become faster and more convenient.thesis analyze particularly the three-layers Schema of measuring database one by one. It lists every object structure in main user's measuring database especially the structure of the table in details .The thesis expounds how to realize the measuring database migration by the three-layers Schema theory with the tools such as PB and ORACLE function package and cmdline scripts and so on."ORACLE Data Migration Assistant" is designed and program debugging, packaged in the PB interface development tools , and its main function is realized by PB through the process of DOS scripts, procedures and PL / SQL procedures to achieve the above. In the process of data migration process will be divided into four steps: extraction of the structure of database objects; database data extraction; import of database objects structure; import of database data. During this period the use of the technology are: using ORACLE database DBMSMETADATA.GETDLL Function package to extract the definition of database objects DDL statements (database user object structure); using SPOOL, SELECT program segment to extract metering data; using SQLLOADER procedures to import measurement data ;using ORACLE formatting commands: SET and DOS function to format the output.The biggest difficulty of this article is: how to achieve up to 40G measurement picture data migration. I used ORACL database own of "transmission table space" technology to succeed in solving this problem.The greatest innovation of topics is : the successful settlement of the garbled characters in diflferent character set between different database operation systems in the process of ORACLE data migration.