1Z0-146 Question #68: Real Exam Question with Answer & Explanation

Question

Options

• AIt can store the query results for temporary tables.
• BIt can be set at the system, session, or query level.
• CIt is used only across statements in the same session.
• DCached query results become invalid when the data accessed by the query is modified.

Explanation

RESULT_CACHE Hint on queries RESULT_CACHE_MODE - Modifiable ALTER SESSION, ALTER SYSTEM SQL Query Result Cache The SQL query result cache is a subset of the server result cache that stores the results of queries and query fragments. Most applications benefit from this performance improvement. Consider an application that runs the same SELECT statement repeatedly. If the results are cached, then the database returns them immediately. In this way, the database avoids the expensive operation of rereading blocks and recomputing results. When a query executes, the database searches memory to determine whether the result exists in the result cache. If the result exists, then the database retrieves the result from memory instead of executing the query. If the result is not cached, then the database executes the query, returns the result as output, and then stores the result in the result cache. The database automatically invalidates a cached result whenever a transaction modifies the data or metadata of database objects used to construct that cached result. Users can annotate a query or query fragment with a RESULT_CACHE hint to indicate that the database should store results in the SQL query result cache. The RESULT_CACHE_MODE initialization parameter determines whether the SQL query result cache is used for all queries (when possible) or only for annotated queries.

No community discussion yet for this question.