Can someone plz refer/recommend any document on query merging? I am working on a database sever. The response time, of view's query has become a challange to me. I have tried everything, the last hope left is query merging.
But I didnt find any docs/papers/books on it.
Are there those,
In this world of brave,
Who can tell me,
How should I behave,
When I am disgraced.
Thanks a lot. Query Merging that I referred was not related to merging of one table's data into another, but if I fire a query, which is containing a subquery in it, then the execution may take two different strategies, 1. Execute the subquery, fetch the result and compare this data with the parent querie's data. 2. Merge the subquery into Parent query and execute them as if the query wasn't subquery but a single level '0' query.
The best xample is Oracle's COMPLEX_QUERY_MERGING option. I want to understand, how Oarcle internally merges these queries? Is there any Optimizer Doc, which gives the detail?
Is your question in regards to Oracle? This is a SQL Server forum, and SQL Server generally does a good job of optimizing queries, even with complex embedded subqueries.
If you are having slow response times on SQL Server, then post your query and someone on the forum might be able to help you optimize it.
If it's not practically useful, then it's practically useless.