Database management

SQL Server 2014: In-Memory tables, Bw-Tree, and storage

SQL Server 2014 introduces hash indexes with in-memory optimized tables. I described some of their aspects in a previous blog post.  These indexes are very efficient with lookup search operations but have some limitations with operations(…)

Oracle TNS_ADMIN issues due to bad environment settings

Recently, I faced a TNS resolution problem at a customer. The reason was a bad environment setting: The customer called the service desk because of a DBLINK pointing to a bad database. The users were supposed to be redirected to a(…)

Oracle 12c Adaptive Plan & inflection point

By Franck Pachot . The Oracle 12c Adaptive Plan feature was already presented by Nicolas Jardot in OOW 2013: Solving customer issues with the 12c Optimizer. I recently had to answer several questions about its behavior at execution(…)

Transparent data encryption, key management and backup strategies

Transparent Data Encryption requires the creation of a database key encryption. The database key is a part of the hierarchy of SQL Server encryption tree with at the top of the tree the DPAPI. Then if we traverse the(…)

The consequences of NOLOGGING in Oracle

By Franck Pachot . While answering to a question on Oracle forum about NOLOGGING consequences, I provided a test case that deserves a bit more explanation. Nologging operations are good to generate minimal redo on bulk operations (direct-path(…)

SQL Server 2014: Buffer pool extension – an interesting new feature

Buffer pool extension (aka BPE) is an interesting feature of SQL Server 2014. Database administrators already know that memory is one of the key assets available for SQL Server. This is especially true for buffer pool memory, which plays(…)

Investigating Oracle lock issues with event 10704

By Franck Pachot . Did you ever encounter unexplained Oracle lock issues? They may be coming from unindexed foreign keys (which is worse in 11g). It’s not easy to monitor. Of course you can check Oracle locks from V$LOCKED_OBJECT, but(…)

Troubleshooting: ORA-29283 when oracle is member of a group with read/write privileges

Recently, I worked on an Oracle database migration for a customer and I faced a strange behavior when accessing a file stored on the file system of the Oracle database. The database has been migrated on a new server, and(…)

SQL Server 2014: Deleting files of a hekaton table

A recurrent question I have often heard about Hekaton objects is the following: Is an accidental deletion of the compilation files of a hekaton table on the file system irreversible and could this compromise the execution of SQL Server?(…)

Oracle 12c In-Memory option: waiting for 12.1.0.2

By Franck Pachot . Oracle has announced a big feature that should come in the next 12c patch set: the In-Memory option. It will soon be in beta version, so nothing will be published about it until it(…)