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ماهو البليس هولدر وما هو ماترياليزد فيو


ahmedkhaled

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السلام عليكم ورحمة الله وبركاته
سألني احد الاخوه عن البليس هولدر و ماترياليزد فيو وقالي انهم جولو في انتر فيو وهو مش عارف الاجابه ولا انا ياريت التشرف بالرد علينا في هذه الاسئله وجزاكم الله خير

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ألسلام عليكم إخي:
1- A Placeholder is a predefined location in a JSP that displays a single piece of web content at a time that is dynamically retrieved from the WLP Virtual Content Repository. If more than one content query is registered for a Placeholder, the Placeholder uses predefined queries and logic to determine which query to run and which content item to display. If a content query does not return data, the Placeholder runs another registered query, if there is one. Each query has a priority, or weight that determines the specific content to display.

2- In a database management system following the relational model, a view is a virtual table representing the result of a database query. Whenever an ordinary view's table is queried or updated, the DBMS converts these into queries or updates against the underlying base tables. A materialized view takes a different approach in which the query result is cached as a concrete table that may be updated from the original base tables from time to time. This enables much more efficient access, at the cost of some data being potentially out-of-date. It is most useful in data warehousing scenarios, where frequent queries of the actual base tables can be extremely expensive.
In addition, because the view is manifested as a real table, anything that can be done to a real table can be done to it, most importantly building indexes on any column, enabling drastic speedups in query time. In a normal view, it's typically only possible to exploit indexes on columns that come directly from (or have a mapping to) indexed columns in the base tables; often this functionality is not offered at all.
Materialized views were implemented first by the Oracle database.
There are three types of materialized views:
Read only
Cannot be updated and complex materialized views are supported
Updateable
Can be updated even when disconnected from the master site.
Are refreshed on demand.
Consumes fewer resources.
Requires Advanced Replication option to be installed.
Writeable
Created with the for update clause.
Changes are lost when view is refreshed.
Requires Advanced Replication option to be installed.

أرجو أن تستفيد من هذه المعلومات.

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ألسلام عليكم إخي:
1- A Placeholder is a predefined location in a JSP that displays a single piece of web content at a time that is dynamically retrieved from the WLP Virtual Content Repository. If more than one content query is registered for a Placeholder, the Placeholder uses predefined queries and logic to determine which query to run and which content item to display. If a content query does not return data, the Placeholder runs another registered query, if there is one. Each query has a priority, or weight that determines the specific content to display.

2- In a database management system following the relational model, a view is a virtual table representing the result of a database query. Whenever an ordinary view's table is queried or updated, the DBMS converts these into queries or updates against the underlying base tables. A materialized view takes a different approach in which the query result is cached as a concrete table that may be updated from the original base tables from time to time. This enables much more efficient access, at the cost of some data being potentially out-of-date. It is most useful in data warehousing scenarios, where frequent queries of the actual base tables can be extremely expensive.
In addition, because the view is manifested as a real table, anything that can be done to a real table can be done to it, most importantly building indexes on any column, enabling drastic speedups in query time. In a normal view, it's typically only possible to exploit indexes on columns that come directly from (or have a mapping to) indexed columns in the base tables; often this functionality is not offered at all.
Materialized views were implemented first by the Oracle database.
There are three types of materialized views:
Read only
Cannot be updated and complex materialized views are supported
Updateable
Can be updated even when disconnected from the master site.
Are refreshed on demand.
Consumes fewer resources.
Requires Advanced Replication option to be installed.
Writeable
Created with the for update clause.
Changes are lost when view is refreshed.
Requires Advanced Replication option to be installed.

أرجو أن تستفيد من هذه المعلومات.

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يإخواني بجد الف شكر ليكو وجزاكم الله كل خير على الاهتمام وعلى الرد السريع جدا ده




إن الله في عون العبد ما دام العبد في عون اخيه

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