The Instance Initialization parameters are set to: DB_CREATE_FILE_DEST = +DATA DB_CREATE_ONLlNE_LOG_DEST_l = +LOGS DB_CREATE_ONLlNE_LOG_DEST_2 = + FRA The SQL* Plus command "ALTER DATABASE ADD…

Samuel O.Jun 10, 2026

The answer is C, one member lands in +LOGS and another lands in +FRA. Here is the reasoning that made this click for me on the job before I even saw it on an exam. When you have DB_CREATE_ONLINE_LOG_DEST_1 and DB_CREATE_ONLINE_LOG_DEST_2 both set, Oracle treats each of those as a required destination for a separate log member in the new group, so it writes one to +LOGS and one to +FRA simultaneously. DB_CREATE_FILE_DEST (+DATA) is the catch-all for OMF files in general, but the specific ONLINE_LOG_DEST parameters take precedence and completely override it for online redo logs, which is why +DATA never enters the picture here. People trip on options D and F because they read "or" as what Oracle actually does, but the "or" fallback logic only applies when one of the ONLINE_LOG_DEST slots is unset or unavailable, not when both are explicitly configured and healthy. In a real ASM environment you want that multiplexing across disk groups anyway, so understanding that both destinations are honored simultaneously is not just exam trivia, it is the whole point of setting two separate parameters.

Grace U.Jun 27, 2026

C is the one, and once you see why the other options fall away pretty fast. The key is that DB_CREATE_ONLINE_LOG_DEST_1 and DB_CREATE_ONLINE_LOG_DEST_2 are the parameters Oracle looks at specifically for online redo log placement, and when both are set, Oracle creates a member in each of those locations, so you get +LOGS and +FRA together. DB_CREATE_FILE_DEST is for datafiles, tempfiles, and control files, not online redo logs, which is the trap that pulls people toward answer A or E. When you issue ALTER DATABASE ADD LOGFILE without a filename, Oracle does not fall back to +DATA for the log members because the dedicated online log destination parameters are already populated and take full precedence. If only one of those two parameters were set, then DB_CREATE_FILE_DEST would step in as a fallback for the second member, but that is not the scenario here.

Viktor S.Jun 19, 2026

I went with B at first because I kept conflating DB_CREATE_FILE_DEST with online redo log creation, which is wrong. DB_CREATE_FILE_DEST only controls where datafiles, control files, and tempfiles land when you use OMF without a more specific parameter set. The parameters that matter for "ALTER DATABASE ADD LOGFILE" are DB_CREATE_ONLINE_LOG_DEST_1 and DB_CREATE_ONLINE_LOG_DEST_2, and when both are set, Oracle creates a member in each of those locations, period, +DATA gets completely ignored for this operation. So C is correct: one member goes to +LOGS, one goes to +FRA, and that is exactly what those two parameters are designed to do.

Bao N.Jun 27, 2026

C is the one that trips people up the least once you actually understand the parameter hierarchy, but getting there takes a few reps. When you issue ALTER DATABASE ADD LOGFILE without specifying a location, Oracle ignores DB_CREATE_FILE_DEST entirely for redo logs and goes straight to DB_CREATE_ONLINE_LOG_DEST_n. Since DEST_1 is +LOGS and DEST_2 is +FRA, you get one member in each of those groups, multiplexed automatically. DB_CREATE_FILE_DEST is the fallback for datafiles and tempfiles, not for online redo logs when the ONLINE_LOG_DEST parameters are set. The thing I kept getting wrong early on was assuming Oracle would chain the fallback from ONLINE_LOG_DEST down to FILE_DEST if a disk group was unavailable, but that is not how it works for this command without a location clause. Quick question for anyone who has drilled this deeper: if you set DEST_1 and DEST_2 but then DROP one of the disk groups before issuing the ADD LOGFILE, does Oracle silently skip that member or does the whole statement fail? Trying to nail down whether the multiplexing is atomic or best-effort in that edge case.

Luis F.Jun 27, 2026

I kept second-guessing myself on this one because I thought DB_CREATE_FILE_DEST (+DATA) would kick in for redo logs, but nope, the DB_CREATE_ONLINE_LOG_DEST_n parameters take priority for online log files specifically, so Oracle drops one member in +LOGS and a second multiplexed member in +FRA, which is exactly C. The options with +DATA as the answer are the trap here, so watch out for those.