SQL Server Query Processing Flow

Query Submission

User or application submits an SQL query.

SQL Parser

Checks query syntax and creates a parse tree

Query Optimization

Generates execution plans and selects the most efficient one

Query Execution

Sent to Query Executor.

Interacts with:

  • Storage Engine (data retrieval/modification).
  • Buffer Manager (manages memory cache).
  • Lock Manager (concurrency control).

Data Retrieval/Modification

Result Presentation

Transaction Management

Query Completion

Storage Engine reads/writes data.

Presents query results to the user/application.

Ensures the query executes within a transaction.

Decides to commit or rollback the transaction.

Releases resources

Returns query results (if any) to the user/application