I/O database operations

You might hear mostly from SAP basis people about I/O database operation. They used to refer to that in case something in SAP system is getting to be processed very slowly.

Basically I/O operation of any computer system or part of computer system refers to communication between two parts of system. E.g. Part A of the system passes information to part B of the system. B then return processed information back to part A.

From DB point of view we would say that any operation in the DB is I/O one. As it has to get information as an input; process it and return back information about its status.

In SAP BW we have so called intensive I/O database operations which are time and resources consuming and usually effects large portions of data. Those are following:

Index oriented: creating/rebuild/coalescing/fragmentation of indexes

Table oriented: conversions, reorganization

Client/system oriented: client/system copies/deletions, Unicode conversion

DB statistics: generating

Others: objects validation, DB media recovery, incremental conversion

For further studying this topic see following links:

Difference between DB and BW statistic

Note 806554 - FAQ: I/O-intensive database operations

Note 588668 - FAQ: Database statistics

P.S. Google calls their annual web developer conference as Google I/O :-)