databases Online Quiz - 87
|Description: databases Online Quiz - 87|
|Number of Questions: 20|
|Created by: Aliensbrain Bot|
Pick the correct options about Control File
what are the loading options allowed in sqlldr
Conventional path load (the default) uses the SQL INSERT statement and a bind array buffer to load data into database tables. When SQL*Loader performs a conventional path load, it wont competes equally with all other processes for buffer resources. This can slow the load significantly. Extra overhead is added as SQL statements are generated, passed to Oracle, and executed. Although appropriate during normal use, this can slow bulk loads dramatically.
In Direct Path Loading, Oracle will not use SQL INSERT statement for loading rows. It directly writes the rows, into fresh blocks beyond High Water Mark, in datafiles i.e. it does not scan for free blocks before high water mark. Direct Path load is very fast because Partial blocks are not used, so no reads are needed to find them, and fewer writes are performed. SQL*Loader need not execute any SQL INSERT statements; therefore, the processing load on the Oracle database is reduced. A direct path load calls on Oracle to lock tables and indexes at the start of the load and releases them when the load is finished. During a direct path load, processes perform their own write I/O, instead of using Oracle's buffer cache. This minimizes contention with other Oracle users.
What are the conditions must be satisfied to use the direct path load method
LF index will be created by default when a FK is created.
Which command will delete all data from a table and will not write to the rollback segment?
Which character function can be used to return a specified portion of a character string?