What is offline reorg in DB2?
What is offline reorg in DB2?
There are four phases in a CLASSIC or offline table reorganization operation: SORT – During this phase, if an index was specified on the REORG TABLE command, or a clustering index was defined on the table, the rows of the table are first sorted according to that index.
What is online reorg in DB2?
Online Reorg is an availability enhancement to DB2 introduced in DB2 Version 5. It increases availability of a tablespace and/or index while it is being reorganised. The reorganisation of an object necessarily consists of the destruction of an object and its rebuilding in reorganised form.
What is table reorganization?
Explanation. First, the table is stored temporarily in an unload file; this process is called table unloading. Subsequently, the data is re-stored in the table; this process is called table data reloading. The entire process is called table reorganization.
How does reorg work in DB2?
If the table space is defined by storage groups, Db2 allocates space, and you cannot alter data set definitions while a REORG job is in process. Db2 deletes and redefines the necessary data sets to reorganize the object. You can temporarily pause REORG TABLESPACE. Db2 estimates how many records are to be sorted.
What is Runstats and reorg in DB2?
runstats is for collecting indexes and tables statistics information which to enable the DB2 optimizer to generate efficient access plan. reorgs is for reorganizing tables and indexes.
What is Reorg and Runstats in DB2?
What is table reorg in SAP?
Use. This section helps you develop an approach to reorganization, which improves the structure of the database, and can result in improved performance. BRSPACE performs the reorganization using the new Oracle feature, online table redefinition or offline table move.
Why do we need reorg in Db2?
To keep it simple: REORG is a database operation that is executed in DB2 to reorganize the table spaces or index spaces. The purpose of the reorganization is data clustering. On the other side, the in place REORG allows full access to the table, because the operation incrementally reorganizes the table.