Teradata is used for massive parllel processing(MPP). There are 4 different components of teradata i,e Node, Parsing engine, Message passing unit or Bynet, Access module processor(AMP).
Node :
Parsing engine : It receives queries from clients, checks for syntax errors, checks user privilages, prepares execution plan and pass it to Bynet, lastly receives results from AMP's and sends to client.
Bynet : Message passing layer is also called as Bynet. It allows communication between PE and AMP. It receives execution plan from PE and pass it to AMP, similarly it receives result from AMP and pass it to PE.
Amp : These are called as virtual processors, they actually stores and receives the data.
Teradata supports different types of tables :-
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Permanent table : This is a default table, it contains inserted data and stored data permanently.
Volatile table : The data inserted into a volatile table is retained only during the user session. Table and data is dropped at the end of the session. These tables are used to hold the data during data transmission.
Global temporary table : Table is delete at the end of user session.
Derived table : Derived table holds the intermediate results in a query. Their lifetime is within the query in which they are created, used and dropped.
Set Versus Multiset :-
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Teradata classifies the tables as SET or MULTISET tables based on how the duplicate records are handled. A table defined as SET table doesn’t store the duplicate records, whereas the MULTISET table can store duplicate records.
Node :
Parsing engine : It receives queries from clients, checks for syntax errors, checks user privilages, prepares execution plan and pass it to Bynet, lastly receives results from AMP's and sends to client.
Bynet : Message passing layer is also called as Bynet. It allows communication between PE and AMP. It receives execution plan from PE and pass it to AMP, similarly it receives result from AMP and pass it to PE.
Amp : These are called as virtual processors, they actually stores and receives the data.
Teradata supports different types of tables :-
---------------------------------------------
Permanent table : This is a default table, it contains inserted data and stored data permanently.
Volatile table : The data inserted into a volatile table is retained only during the user session. Table and data is dropped at the end of the session. These tables are used to hold the data during data transmission.
Global temporary table : Table is delete at the end of user session.
Derived table : Derived table holds the intermediate results in a query. Their lifetime is within the query in which they are created, used and dropped.
Set Versus Multiset :-
---------------------
Teradata classifies the tables as SET or MULTISET tables based on how the duplicate records are handled. A table defined as SET table doesn’t store the duplicate records, whereas the MULTISET table can store duplicate records.
