 Related Questions ORACLE database's data is stored in data blocks. One data block corresponds to a specific number of bytes of physical database space on disk. Latest Answer : Oracle Data Blocks is logical storage unit of Oracle and One Oracle Data Blocks containts multiple of Operating system Blocks. Data blocks contains contigous of Bytes. ... 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 ... The data dictionary of an ORACLE database is a set of tables and views that are used as a read-only reference about the database.It stores information about both the logical and physical structure of the Latest Answer : Data Dictionary is a read-only set of tables that provides information about the database. in order to avoid the I/O cost, these data dictionary views are used ... An integrity constraint is a declarative way to define a business rule for a column of a table. Latest Answer : Special requirements for table data:1) allow NULL value2) uniqueness of value3) primary key4) foreign key5) special value size/text/length etc requirementsAll information is stored in Data Dictionary. ... 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 column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can't contain Nulls. Latest Answer : A table can have any number unique keys but a single primary key ... 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 ... The condition must be a Boolean expression evaluated using the values in the row being inserted or updated and can't contain sub queries, sequence, the SYSDATE,UID,USER or USERENV SQL functions, or Latest Answer : A check constraint allows you to specify a condition on each row in a table. Note: A check constraint can NOT be defined on a VIEW. The check constraint defined on a table must refer to only columns in that table. It can not refer to columns in other ... No Limit. Latest Answer : You can create any number of check constraintsseparated by AND, OR, or NOT to create more complex conditions. ...
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