asrblogger The database buffer cache, also called the buffer cache, is the memory area that stores copies of data blocks read from data files. A buffer is a main memory address in which the buffer manager temporarily caches a currently or recently used data block. All users concurrently connected to a database instance share access to the buffer cache. It … Read more
Oracle can store different kind of files under FRA: – backupset: for RMAN regular backups. – datafile: for RMAN image copies. – autobackup: for control file autobackups. – flashback: If your database runs in flashback mode, you will see flashback logs in this subdirectory. – archivelog: for Archived redo logs – controlfile: The control file, … Read more
The pattern-matching conditions compare character data. LIKE Condition * The LIKE conditions specify a test involving pattern matching. Whereas the equality operator (=) exactly matches one character value to another. * The LIKE conditions match a portion of one character value to another by searching the first value for the pattern specified by the second. … Read more
The database control file is a small binary file associated with only one database. Each database has one unique control file, although multiple identical copies are permitted. Use of Control Files Oracle Database uses the control file to locate database files and to manage the state of the database generally. A control file contains information … Read more
If you flush the shared pool, all the statements in cursor will be flushed. Sometimes it is required to flush the bad SQL_PLAN from shared_pool so that new (or old) better execution plan can be picked by SQL_ID So if you want a SQL query to do hard parsing, then you can flush the particular … Read more
A checkpoint is a crucial mechanism in consistent database shutdowns, instance recovery, and Oracle Database operation generally. The term has the following related meanings: • A data structure that indicates the checkpoint position, which is the SCN in the redo stream where instance recovery must begin. The checkpoint position is determined by the oldest dirty … Read more
The dynamic performance views are special views that are continuously updated while a database is open and in use. Throughout its operation, Oracle Database maintains a set of virtual tables that record current database activity.These views are dynamic because they are continuously updated while a database is open and in use. The views are sometimes … Read more
A lock is a mechanism that prevents destructive interactions. Interactions are destructive when they incorrectly update data or incorrectly alter underlying data structures, between transactions accessing shared data. Locks play a crucial role in maintaining database concurrency and consistency. Summary of Locking Behavior The database maintains several different types of locks, depending on the operation … Read more
Problem:While patching 19.3 GRID_HOME with July2019 RU patch 19.4 I got this error: Solution:The problem was with the RU patch binaries, looks the files were not copied properly, extracting the binaries properly from the zip file has fixed the problem!Initially, copied the “extracted” RU binary files from another node, seems they were incomplete.