What does coalesce tablespace do in Oracle?
What does coalesce tablespace do in Oracle?
Coalesce simply takes contigous free extents and makes them into a single bigger free extent. It is not a reorganization tool. It is a command to take any free extents that are right next to some other free extent and make one bigger free extent out of them.
How many datafiles are there in a database?
A database’s data is collectively stored in the datafiles that constitute each tablespace of the database. For example, the simplest Oracle database would have one tablespace and one datafile. Another database can have three tablespaces, each consisting of two datafiles (for a total of six datafiles).
What is Sysaux used for?
The SYSAUX tablespace provides storage of non-sys-related tables and indexes that traditionally were placed in the SYSTEM tablespace. For example, the tables and indexes that were previously owned by the system user can now be specified for a SYSAUX tablespace.
What is coalesce partition in Oracle?
For partitioned tables, Oracle provides the “Coalesce partition” syntax. The Oracle docs note that the coalesce partition syntax behave differently, depending on the type of partition: “When a hash partition is coalesced, its contents are redistributed into one or more remaining partitions determined by the hash function.
What is the difference between coalesce and deallocate unused space?
Answer: Both the coalesce and “deallocate unused space” commands serve to free-up space, but they do it in different ways: Oracle notes that the “deallocate unused space” clause is used to to explicitly deallocate unused space at “the end” of a segment and makes that space available for other segments within the tablespace.
What is the coalesce command used for?
It is useful after a drop command when you want to create another object right away. SMON will normally perform this coalescing in the background but if you need it to happen “right now”, the coalesce command will do it. Tablespace altered. Is this answer out of date?
What does deallocate unused space mean in Oracle?
Deallocate unused space. Oracle notes that the “deallocate unused space” clause is used to to explicitly deallocate unused space at “the end” of a segment and makes that space available for other segments within the tablespace.
