(mdinh) Typically, it’s not a good idea to have “crosscheck archivelog all;” in backup scripts and even worse to have “delete expired archivelog all;” since any evidence will be eradicated.

(Kellyn Pot’Vin) To assist users as they plan out their upgrades and new Enterprise Manager environments, I wanted to go over a few subtle, but important changes from EM12c, 12.1.0.5 to the newest release, the much anticipated EM13c, 13.1.0.0.

(connormcdonald) People often think when using the SAMPLE clause, that because they are only dealing with a subset of the data, that immediately it should be a much faster operation. And whilst sometimes this is indeed the case, it is not a guarantee.

(Hemant K Chitale) Now, starting a new series of blog posts on Compression.

(mdinh) When you are backing up 3.5+ TB database, resulting in 600+ GB backupset, transferring to new DC, you would want to ensure there are no corruptions resulting from transfer.

(connormcdonald) If you’ve got a stack of large I/O operations to perform, you might want to take advantage of the all of the cores on your server. However, if the scripts are already in place, you might not want to be editing them individually to carefully add parallelism.

(Andrew Reid) I ran the following SQL in an Oracle 11.2.0.1 database:

(mdinh) Question which may have been asked.

(Hemant K Chitale) To quote the 11.2 documentation, “Although it is referred to as block compression, it might be helpful to think of block compression as block skipping”. 11.2 differentiates between Unused Block Compression and Null Block Compression.

(connormcdonald) We all know that comparing two VARCHAR2 fields of different lengths will be treated by Oracle as being not EQUAL: