Short note on Query Processing .

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Query Processing 

  • Query Processing is a translation of high-level queries into low-level expressions. It is a step-wise process that can be used at the physical level of the file system, query optimization, and actual execution of the query to get the result.
  • It requires the basic concepts of relational algebra and file structure. It refers to the range of activities that are involved in extracting data from the database. It includes the translation of queries in high-level database languages into expressions that can be implemented at the physical level of the file system.
  • Query Processing is the process of converting high-level queries to low-level expressions to extract the data from physical level file systems like databases.  OR,
  • Query Processing would mean the entire process or activity which involves query translation into low-level instructions, query optimization to save resources, cost estimation or evaluation of query, and extraction of data from the database

It involves mainly four steps

  • Parsing and translation
  • Optimization
  • Evaluation
  • Execution





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