Tag - Bugs

MySQL VIEW as Performance Troublemaker

I start to see applications being built utilizing VIEWs functionality which appeared in MySQL 5.0 and quite frequently VIEWs are used to help in writing the queries – to keep queries simple without really thinking how it affects server performance.
Even worse than that – looking at the short table which just gets single row […]

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Query_cache and column level privileges

Recently we were puzzled by question how query_cache works with column level privileges. The question was appeared as we discovered function query_cache_send_result_to_client is called before real parsing of query, so at the moment of execution the query_cache is not able to know which columns are accessed.
Looking into source code I found out that in […]

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