by admin | Jun 16, 2015 | sem3
Heuristic cost estimation Using Heuristic cost estimation Process for heuristics optimization １．The parser of a high-level query generates an initial internal representation; ２．Apply heuristics rules to optimize the internal representation. ３．A query execution plan is...
by admin | Jun 16, 2015 | sem3
Query Processing and Optimization Query Processing and Optimization : Outline Operator Evaluation Strategies Query processing in general Selection Join Query Optimization Heuristic query optimization Cost-based query optimization Query Tuning Query Processing +...
by admin | Jun 16, 2015 | sem3
Embedded SQL Embedded SQL is a methodology of inserting inline SQL statements or queries into the source of a programming language, which is called as a host language. Because the host language can’t parse SQL, the inserted SQL is parsed by an embedded SQL...
by admin | Jun 16, 2015 | sem3
Database Objects A database objects in a relational database is a data structure used to either save or reference data. The most basic object that people interact with is the table. Other objects are indexes, stored procedures, sequences, views and many other. When a...
by admin | Jun 16, 2015 | sem3
SQL Data types SQL data type is an attribute that specifies type of data of any object. Each column, variable and expression has related data type in SQL. You would use these data types while creating your tables. You would choose a particular data type for a table...
by admin | Jun 16, 2015 | sem3
DDL DML DCL TCL DDL : DDL is abbreviation of data Definition Language. it’s used to create and modify the structure of database objects in database. SELECT – retrieve data from the a database INSERT – insert data into a table UPDATE – updates...
