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ncc:tldr:93675
The command "ncc clean cache" is used to clean the cache of the Netezza compiler (ncc).
In Netezza, the ncc compiler compiles the SQL statements and generates an execution plan for query execution. The compiled SQL and execution plans are stored in a cache to improve the performance of subsequent similar queries.
However, over time, the cache can become bloated with outdated or unnecessary compiled SQL and plans, which may negatively impact performance. Therefore, the "ncc clean cache" command is used to remove the contents of the cache and start fresh.
When you execute the command "ncc clean cache", it will delete all the compiled SQL and plans stored in the cache. This will force the Netezza system to recompile the SQL statements and generate new execution plans when those queries are executed again.