Which status indicator assesses how effective the table cache is?

Solution (By Examveda Team)

This question is about understanding how MySQL manages tables in memory.

MySQL has a table cache that stores frequently used table definitions in memory. This makes accessing these tables faster.

To determine how effectively the table cache is being used, we need to look at a status variable that tells us about the number of tables opened and closed.

Let's look at the options:

Option A: Open_tables - This option refers to the number of tables currently open in the table cache. This is a good indicator of how many tables are being actively used.

Option B: Opened_tables - This option refers to the total number of tables opened since MySQL started. It doesn't directly reflect the effectiveness of the cache.

Option C: Close_tables and Option D: Closed_tables are not valid status variables in MySQL.

Therefore, the correct answer is Option A: Open_tables.

By monitoring the Open_tables value, we can understand how many tables are actively being held in the cache, which helps assess the effectiveness of the cache. If Open_tables is consistently high, it means the cache is being heavily used. If it's low, it might indicate that the cache is not being utilized effectively.