 Related Questions There are two types of Synonyms Private and Public. An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information. Latest Answer : An extent is a logical unit of database storage space allocation made up of a number of contiguous data blocks. One or more extents in turn make up a segment. When the existing space in a segment is completely used, Oracle allocates a new extent for the ... Data Segment, Index Segment, Rollback Segment and Temporary Segment. Latest Answer : Data, index , rollback, undo,cluster ... A Database contains one or more Rollback Segments to temporarily store "undo" information. Latest Answer : It stores your uncommited temporart data. ex. If you do any insert/update/delete and you won't commit it is written in rollback segment. ... Rollback Segments are used :To generate read-consistent database information during database recovery to rollback uncommitted transactions for users. Latest Answer : Rollback Segment Stores Undo Information and are used for the following purposes.1. To undo the previous command2. For read consistency and3. For crash recovery. ... Temporary segments are created by ORACLE when a SQL statement needs a temporary work area to complete execution. When the statement finishes execution, the temporary segment extents are released to the Latest Answer : temporary segments are basically used for sort operations in oracle,,when the user tries to execute the query through order by clause. so system needs an space for an sort operation, and system will use temporary segments for this query. ... NOT NULL Constraint - Disallows Nulls in a table's column.UNIQUE Constraint - Disallows duplicate values in a column or set of columns.PRIMARY KEY Constraint - Disallows duplicate values and Nulls A rule defined on a column (or set of columns) in one table that allows the insert or update of a row only if the value for the column or set of columns (the dependent value) matches a value in a column Latest Answer : Referential integrity is a relationship between two tables, one being the 'parent' and the other being the 'child'. The 'child' table references values in the 'parent' table's primary key to ensure all data between ...
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