What are locking issues in OLAP?

Question

In one local financial institution I was rebuked by their programmers for expressing them my opinion that (their programmers' obsession with) (b)locking issues in their MS SQL Server 2005 OLAP (SSAS) database(s) did not make much sense to me. (The OLTP databases are SQL Server, Oracle and non-RDBMS ERP).

What are locking issues in OLAP processing if OLAP (SSAS) databases are used only for reading (read-only after deployment)?

In which context do such (an whic?) issues arise - during SSIS processing and transfer of data from OLTP databases?
during deployment of SSAS (OLAP) databases to SSAS?

This question is not restricted to SQL Server.

Answer 1

OLAP is not anyway restricted to readonly scheme. If your system' data layer designed in terms of dimensions from the ground up, you may use it for analytical processing as well as for CRUD operations. And yes, there you can face some locking problems due to data consistency you have to provide during analysis procedures.

And if OLAP is readonly then the same issue arises exactly while transferring from OLTP. It's a common mistake to fetch updated data into OLAP asap in small chunks thus making bottlenecks.