How SQL query is executed internally?

How does SQL query work internally?

SQL Query mainly works in three phases .11) Row filtering - Phase 1: Row filtering - phase 1 are done by FROM, WHERE , GROUP BY , HAVING clause.22) Column filtering: Columns are filtered by SELECT clause.33) Row filtering - Phase 2: Row filtering - phase 2 are done by DISTINCT , ORDER BY , LIMIT clause.

How an SQL query is executed?

Query Process Steps1Getting Data (From, Join)2Row Filter (Where)3Grouping (Group by)4Group Filter (Having)5Return Expressions (Select)6Order & Paging (Order by & Limit / Offset)

How SQL query is executed internally in Oracle?

How an SQL query is executed in Oracle Database1An instance has started on a node where Oracle Database is installed, often called the host or database server.2A user starts an application spawning a user process. ... 3The server runs a listener that has the appropriate Oracle Net Services handler.

How query is executed SQL Server?

How to Check SQL Server Query History1Queries are saved in the cache via system representations (sys. dm_exec_query_stats, sys. dm_exec_sql_text, and sys. ... 2Using SQL Server Profiler.3Using Extended Events.4Using the Query Store, starting from the 2016 version.5Using SQL Complete (SQL Complete\Execution History) in SSMS.