Tagged: parameter

Oracle Database

DB_ULTRA_SAFE parameter

DB_ULTRA_SAFE is a new parameter introduced in 11g. It provides an integrated mechanism to offer protection from various possible data corruptions. and provides critical high availability benefits for Oracle Database. Setting DB_ULTRA_SAFE initialization parameter will configure the appropriate data protection block checking level in the database. It will control DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM, and DB_LOST_WRITE_PROTECT. DB_BLOCK_CHECKING controls whether or not Oracle performs block checking for database blocks. DB_BLOCK_CHECKSUM determines whether DBWn and the direct loader will calculate a checksum and store it in the cache header of every data block when writing it to disk. DB_LOST_WRITE_PROTECT enables or disables lost write detection....

Oracle Database 12 c

ORACLE 12C : approx_count_distinct parameter

The APPROX_COUNT_DISTINCT function was added, but not documented, in Oracle 11g to improve the speed of calculating the number of distinct values when gathering statistics using the DBMS_STATS package. Oracle database 12c (12.1.0.2) now includes the function in the documentation, so we are free to use it in our applications as a supported SQL function. It returns approximate number of rows that contain distinct values of expression. It’s alternative to the COUNT (DISTINCT expr) function, which returns the exact number of rows that contain distinct values of expr. For processing large amounts of data it’s significantly faster than COUNT, with...