useful DataDictionary Views

DATABASE PROPERTIES=

DATABASE_PROPERTIES,V$NLS_PARAMETERS

DATABASE=

V$DATABASE, V$VERSION, V$INSTANCE

SHARED SERVER =
V$QUEUE, V$DISPATCHER, V$SHARED_SERVER

CONNECTION POOLING=
DBA_CPOOL_INFO, V$CPOOL_STAT, V$CPOOL_CC_STATS

SPACE=
DBA_DATA_FILES,DBA_FREE_SPACE,DBA_TS_QUOTAS

CONTROLFILES=
V$CONTROLFILE, V$PARAMETER, V$CONTROLFILE_RECORD_SECTION

DATAFILES=
V$DATAFILE,V$DATAFILE_HEADER, DBA_DATA_FILES

SEGMENTS=
DBA_SEGMENTS, USER_SEGMENTS

EXTENTS=
DBA_EXTENTS, USER_EXTENTS

REDOLOG=
V$THREAD, V$LOG, V$LOGFILE, V$LOG_HISTORY

UNDO=
V$UNDOSTAT, V$ROLLSTAT, V$TRANSACTION

ARCHIVE=
V$DATABASE, V$LOG, V$ARCHIVED_LOG, V$ARCHIVE_DEST

INSTANCE=
V$INSTANCE, V$PARAMETER, V$SYSTEM_PARAMETER

MEMORY=
V$SGA, V$SGASTAT, V$SGAINFOV$SGA_DYNAMIC_COMPONENTS,V$SGA_RESIZE_OPS

ADVICE=
V$SGA_TARGET_ADVICE, V$PGA_TARGET_ADVICE

PROCESSES=
V$PROCESS, V$BGPROCESS

PERFORMANCE=
V$SYSSTAT,V$SESSMETRIC,V$SYSTEM_EVENT

ALERTS=
DBA_THRESHOLDS, DBA_OUTSTANDING_ALERTS,DBA_ALERT_HISTORY, 

V$ALERT_TYPES,V$METRIC

LOCK & LATCH=
V$LOCK,v$LOCKED_OBJECTS,DBA_LOCK, V$SESSION_WAIT,V$LATCH

TABLES=
DBA_TABLES, ALL_TABLES, USER_TABLES

INDEXES=
DBA_INDEXES, ALL_INDEXES, USER_INDEXES

DATAPUMP=
DBA_DATAPUMP_JOBS,DBA_DATAPUMP_SESSIONS,(V$SESSION_LONGOPS|SOFAR|TOTALWORK|UNITS)

OBJECTS=DBA_OBJECTS, ALL_OBJECTS, USER_OBJECTS

ASM=
V$ASM_DISKGROUP,V$ASM_FILE,V$ASM_OPERATION,V$ASM_ALIAS,V$ASM_CLIENT,V$ASM_DISK)

FLASH RECOVERY=
V$RECOVERY_FILE_DEST

TRASPORT PLATFORM=
V$TRANSPORTABLE_PLATFORM

RECYCLE BIN=
DBA_RECYCLEBIN

MODIFIED TABLE=
DBA_TAB_MODIFICATIONS (since last stats gather)

SQL TRACES=
DBA_ENABLED_TRACES

DATA DICTIONARY HIT RATIO=
V$ROWCACHE

LIBRARY CACHE | RELOAD RATIO
V$LIBRARYCACHE

HIST TABLES=
v$ACTIVE_SESSION_HISTORY,DBA_HIST_SQLSTAT,DBA_HIST_SQLTEXT,DBA_HIST_SQLPLAN